Apego en Autismo y Otros Transtornos

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    Abstract Attachment was assessed in toddlers with

    Autistic Disorder (n = 20), Pervasive DevelopmentalDisorder (n = 14), Mental Retardation (n = 12), Lan-

    guage Development Disorder (n = 16), and a non-

    clinical comparison group (n = 18), using the Strange

    Situation Procedure (SSP). Children in the clinical

    groups were more often disorganized and less often

    securely attached. Severity of autism was associated

    with more attachment insecurity, and lower develop-

    mental level increased the chance for disorganized

    attachment. Attachment disorganization was related to

    increased heart rate during the SSP. Controlling for

    basal cortisol and developmental level, more autistic

    symptoms predicted lower cortisol responses to theSSP. The findings support the importance of disorga-

    nized attachment for children with autism.

    Keywords Autistic disorder Cortisol Physiology

    Strange situation procedure

    Introduction

    For a long time the inability to form attachment rela-

    tionships was seen as one of the characteristics of

    autism (Rutter, 1978; Volkmar et al., 1987), given the

    core problems in social interaction and communication

    in children with autism. However, studies that focused

    on direct observations of attachment behaviors like

    proximity seeking reported that autistic children did

    show behavior that is described as attachment related

    (Buitelaar, 1995; Capps, Sigman & Mundy, 1994;

    Dissanayake & Crossley, 1996; Sigman & Ungerer,

    1984). When a standardized test procedure (i.e. the

    Strange Situation Procedure, SSP; Ainsworth, Blehar,

    Waters, & Wall, 1978) is used to elicit attachment

    behaviors in young children with autism, childrens

    behavioral patterns can be coded according to the

    Ainsworth et al. (1978) attachment classification sys-

    tem. These attachment classifications are the secure

    classification (B), the insecure-avoidant classification

    (A), and the insecure-resistant classification (C), and

    they are based on the childs behavior during reunion

    episodes after two short separations from the care-

    giver. Additionally, a category of disorganized attach-

    ment (D) has been developed to account for

    momentary break-downs in the regular attachment

    strategy (Main & Solomon, 1990).

    Children are classified as securely attached (type B)

    when they use the attachment figure as a base from

    which to explore. These children appear to strike a

    balance between attachment and exploration behavior.

    Insecure-avoidant children (type A) show little or no

    response to the attachment figures leave taking. Their

    exploration is considered a strategy aimed at minimi-

    zation of attachment behavior (Main, 1990). Children

    F. B. A. Naber (&) M. J. Bakermans-Kranenburg M. H. van IJzendoornDepartment of Education and Child Studies,

    Centre for Child and Family Studies, University of Leiden,P.O.Box 9555, 2300 RB Leiden, The Netherlandse-mail: [email protected]

    C. Dietz E. van Daalen H. van Engeland F. B. A. NaberRudolph Magnus Institute of Neuroscience,Department of Child and Adolescent Psychiatry,University Medical Center Utrecht, Utrecht,The Netherlands

    S. H. N. Swinkels J. K. BuitelaarDepartment of Psychiatry, Radboud Universityof Nijmegen, Nijmegen, The Netherlands

    J Autism Dev Disord (2007) 37:11231138

    DOI 10.1007/s10803-006-0255-2

    123

    O R IG IN A L P A P ER

    Attachment in Toddlers with Autism and OtherDevelopmental Disorders

    Fabienne B. A. Naber Sophie H. N. Swinkels Jan K. Buitelaar Marian J. Bakermans-Kranenburg Marinus H. van IJzendoorn Claudine Dietz Emma van Daalen Herman van Engeland

    Published online: 8 December 2006 Springer Science+Business Media, LLC 2006

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    classified as insecure-resistant (type C) appear preoc-

    cupied with their attachment figures throughout the

    procedure. They appear to maximize the display of

    attachment behavior at the expense of exploration

    (Main, 1990). The functional definitions of the attach-

    ment classifications are summarized in Table 1 (Hesse,

    1999, p. 399).

    Disorganized attachment is observed in childrenwho are not able to develop a specific organized

    attachment behavioral pattern with their primary

    caregiver (Main & Solomon, 1986). The disorganized

    (D) classification is considered to index the childs

    inability to cope with his or her anxiety in the face of

    stress although the attachment figure is present. In fact,

    for disorganized children the attachment figure is also

    perceived as a source of fright instead of only as a

    potentially safe haven.

    Based on a meta-analysis of the available empirical

    studies, Rutgers, Bakermans-Kranenburg, Van IJzen-

    doorn, and Van Berckelaer-Onnes (2004) found thatattachment security is compatible with autism, and can

    be assessed with Strange Situation type of procedures.

    The co-morbidity of autism and mental retardation

    appeared to be associated with attachment insecurity.

    With respect to disorganized attachment behavior in

    children with autism, conflicting results were reported.

    In the study of Capps and colleagues (Capps et al.,

    1994) all children with autism appeared to have a

    disorganized attachment relationship, but Willemsen-

    Swinkels and colleagues (Willemsen-Swinkels, Baker-

    mans-Kranenburg, Buitelaar, Van IJzendoorn, & Van

    Engeland, 2000) reported a higher percentage of

    disorganized classifications only in children with autism

    and concurrent mental retardation. It should be noted

    that some of the behaviors that are indicative of dis-

    organized attachment (e.g., stereotypes, undirected

    movements and expressions, and freezing or stilling of

    all movement with a disoriented expression, Main &

    Solomon, 1990) may be more frequently observed in

    children with autism as part of their disorder. Disor-ganized attachment behaviors should, however, be

    informative about relational aspects of the child and its

    caregiver, and not be the result of neurological

    impairments, as Pipp-Siegel, Siegel, and Dean (1999)

    have noted. When attachment security or disorgani-

    zation is coded in samples with children with autistic

    disorders, their baseline behavior in the pre-separation

    episodes of the Strange Situation procedure should be

    taken into account (as was done in Willemsen-Swinkels

    et al., 2000). Using this approach, Willemsen-Swinkels

    et al. (2000) reported diverging patterns of behavioral

    organization in a separate observation of motherinfant interaction for children with autism versus chil-

    dren with disorganized attachment, which suggests that

    it is possible to disentangle autistic behaviors and

    disorganized attachment. They also found that high-

    functioning children with PDD did not reveal higher

    rates of a disorganized attachment than matched

    comparison groups. Unfortunately, the studies of

    Willemsen-Swinkels et al. (2000) and Capps et al.

    (1994) are the only two studies to date with disorga-

    nized attachment assessed in children with autism and

    both these studies were based on children older that

    36 months of age.

    Table 1 Descriptions of attachment classification behavior

    Infant behaviorSecure Attachment (B)Secure children use the attachment figure as a base from which to explore. These children appear to strike a balance between

    attachment and exploration behavior. These children may show signs of missing the parents during separation. With returnof the parents, the child actively greets the parent, usually initiating physical contact. After return of the parent, the child iseasily settled and returns to play.

    Insecure Avoidant Attachment (A)Insecure-avoidant children show little or no response to the attachment figures leave taking. Their exploration is considered a

    strategy aimed at minimization of attachment behavior. These children show little to no proximity or contact seeking, no distress

    and no anger.Insecure Resistant Attachment (C)Children classified as insecure-resistant appear preoccupied with their attachment figures throughout the procedure. They appear

    to maximize the display of attachment behavior at the expense of exploration. They may seem angryor upset and fail to settle after reunion.

    Insecure Disorganized Attachment (D)Disorganized attachment is observed in children who are not able to develop a specific organized attachment behavioral pattern with

    their primary caregiver. The disorganized classification is considered to be an index of the childs inability to cope with his or heranxiety in the face of stress although the attachment figure is present. In fact, for disorganized children the attachment figure is alsoperceived as a source of fright instead of only as a potentially safe haven. The children may show behavior like freezing, stereotypedbehavior, cling or cry hard while looking and leaning away.

    Note: Descriptions of the infant A, B, C and D classifications are summarized from Hesse ( 1999, p. 399)

    1124 J Autism Dev Disord (2007) 37:11231138

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    The advances within the neurosciences in the past

    decade allowed developmental scientists include

    neuro-physiological and behavioral phenomena in an

    integrative approach (Cacioppo & Berntson, 1992).

    Childrens coping strategies, expressed in their behav-

    ioral responses during the Strange Situation, were also

    monitored on a biological level (Gunnar, Mangelsdorf,

    Larson, & Hertsgaard, 1989). This gave rise to anumber of studies on the role of cortisol in attachment.

    Several studies have shown cortisol reactivity in 1-year-

    olds to be related to attachment security (Gunnar,

    Brodersen, Nachmias, Buss, & Rigatuso, 1996;

    Hertsgaard, Gunnar, Erickson, & Nachmias, 1995;

    Nachmias, Gunnar, Mangelsdorf, Parritz, & Buss,

    1996; Spangler & Schieche, 1998). The adrenocortical

    system appears to react most strongly in potentially

    threatening situations, when the resources to cope with

    the threat are lacking (Kirschbaum & Hellhammer,

    1994; McEwen & Sapolsky, 1995; Nachmias et al.,

    1996; Spangler & Scheubeck, 1993). Nevertheless, moststudies indicate that there is considerable individual

    variation in cortisol responsiveness (Jansen et al.,

    1999). Studies on adrenocortical responses to the SSP

    have shown that in particular children with a disorga-

    nized attachment relationship show elevated responses

    in cortisol levels after separation from the mother

    (Hertsgaard et al., 1995; Spangler & Grossmann,

    1993). Cortisol responses during the Strange Situation

    in children with autism under 3 years of age have not

    yet been reported.

    Cardiac responses have been used in typically

    developing children to analyze whether stimuli are

    aversive (heart rate acceleration) or interesting (slow-

    ing heart rate) (Eisenberg & Fabes, 1999; Fabes,

    Eisenberg, & Eisenbud, 1993; Sigman, Dissanayake,

    Corona, & Espinosa, 2003). Therefore, as a second

    physiological indicator of coping with stress, heart rate

    (HR) has also been examined in this study during the

    SSP. Changes in heart rate might be related to

    attachment classification. In particular disorganized

    children may be at risk for deviating heart rate reac-

    tivity, because they lack a coherent coping strategy to

    deal with the stresses of the SSP. In a community

    sample, Spangler and Grossmann (1993) found that

    disorganized infants exhibited a particularly high HR

    elevation during the second separation. Willemsen-

    Swinkels et al. (2000) reported an association between

    disorganized attachment and increase in heart rate in

    children with Pervasive Developmental Disorders.

    Nevertheless, also securely and insecure-avoidant

    children showed (lower, but still significant) increased

    heart rate. Unlike disorganized children, children with

    secure, insecure-avoidant and insecure-resistant infants

    are viewed as having a coherent strategy for coping

    with stress in the presence of an attachment figure

    (Cassidy & Shaver, 1999). Spangler and Grossmann

    (1993) analyzed changes in heart rate in normally

    developing children, and the study of Willemsen-

    Swinkels et al. (2000) involved children with PDD with

    a mean age of 68 months. The relation between

    attachment and heart rate reactivity during stress forchildren with clinical disorders like autism under the

    age of 4 years has not yet been studied.

    In Corona, Dissanayake, Arbella, Wellington, and

    Sigmans (1998) study children with autism did not

    show any heart rate response to the affect of another

    person, whereas children with developmental delays

    showed a cardiac orienting response. The other per-

    sons affect thus seemed interesting to children with a

    developmental delay but not to children with autism.

    Sigman et al. (2003) investigated the cardiac responses

    of children with autism and children with develop-

    mental delay to, among others, parental separation andreunion. They found that children with developmental

    delays showed lower heart rate during the first 10 s of

    separation than baseline, whereas children with autism

    did not show any orienting response.

    Various theoretical models have been proposed

    about the underlying deficits of autism, which may also

    contribute to the prediction of attachment quality in

    this clinical population. One theory is based on the

    effects of impaired developmental level that is seen in

    a high percentage of children with autism. The delay in

    developmental level may contribute to delays or defi-

    cits in the development of understanding other

    peoples actions or situations (Baron-Cohen, 1995;

    Stern, 1985). Therefore, children with autism may de-

    velop a secure attachment relationship, but this

    development may take more time than children with-

    out a developmental delay (Rogers, Ozonoff, & Mas-

    lin-Cole, 1993). Another model describes autism as an

    arousal problem. According to this theory, children

    with autism are highly aroused in social interaction.

    This high arousal may contribute to the aversion of a

    child with autism to interact with another person,

    which may lead to insecure attachment relationships

    (Dawson & Lewy, 1989; Rogers et al., 1993). The

    design of this study creates the opportunity to test

    these hypotheses. The combination of behavioral data

    and heart rate measures during the SSP may contribute

    to a better understanding of the social interactions of

    the children with autism.

    To examine the distribution of the attachment

    classifications we compared the attachment classifica-

    tions of these children with children with other social

    developmental disorders and a non-clinical control

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    group. So far, studies of attachment in children with

    autism involved children older than 3 years of age, and

    modified SSPs were used (for a narrative review and

    meta-analysis of these studies see Rutgers et al., 2004).

    Our main goal is to test whether the distribution of

    attachment classifications of younger children with

    autistic spectrum disorders, using an unmodified SSP at

    a more proper age, is similar to the distribution foundin the normal western population as reported in the

    meta-analysis of Van IJzendoorn and colleagues (Van

    IJzendoorn, Schuengel & Bakermans-Kranenburg,

    1999), or to the combined clinical samples in that meta-

    analysis. The meta-analysis, based on nearly 80 studies,

    showed that 15% of the normal middle class children

    develop insecure avoidant attachments (A), 62%

    secure attachments (B), 9% insecure-resistant attach-

    ments (C), and that 15% are disorganized. In clinical

    samples, the percentage of disorganized children was

    35%. About 13% of the clinical children were found to

    be insecure-avoidantly attached (A), 46% securelyattached (B), and 5% insecure-resistantly (C) attached.

    One of the three characteristic features of the autistic

    disorder is qualitative impairment in social relation-

    ships (American Psychiatric Association, 1994).

    Because the first social relationship of the child is with

    the parent, social development may be influenced by

    parenting processes. Although several studies have

    focused on the ability of children with autism to

    develop an attachment relationship with the parents,

    there are still some questions that need to be ad-

    dressed. One of the questions is the effect of the

    developmental level of the child. A high percentage of

    children with autism also have co-morbid mental

    retardation. Rogers et al. (1993) noted that the devel-

    opmental level was the strongest predictor of attach-

    ment security in their study. However, this study did

    not include a control group of children with mental

    retardation without autistic symptomatology. Also the

    study of Willemsen-Swinkels et al. (2000) did not in-

    clude such a control group. In our study we included

    children with AD and children with PDDNOS, but

    also children with MR and LD and a typically devel-

    oping control group. The inclusion of these groups

    creates the opportunity to investigate the effects of

    autism in the development of an attachment relation-

    ship while being able to control for mental age.

    Our hypothesis is that the group of children with

    autism in our sample will show the same attachment

    distribution as the children with other developmental

    disorders (controlling for baseline behavior), but that

    this distribution will be different from the distribution

    in the non-clinical comparison group. Following

    Rutgers et al.s (2004) meta-analytic results, we expect

    an under-representation of secure attachment in chil-

    dren with autism.

    Sigman and Ungerer (1984) suggested a relationship

    between cognitive development and attachment

    behaviors and Rogers et al. (1993) noted that devel-

    opmental level was the strongest predictor of attach-

    ment security within the group of autism. In the study

    of Willemsen-Swinkels et al. (2000) again the highestproportion of insecure attached children were found

    among the PDD children with co-morbid mental

    retardation. Following these results and the meta-

    analytic findings of Rutgers et al., (2004) we expect

    both autistic characteristics and developmental level to

    be associated with security of attachment in clinical

    children.

    We also expect deviations regarding disorganized

    attachment. Our hypothesis is that children with devel-

    opmental disorders, in particular children who are

    mentally retarded, will show more disorganized attach-

    ment (see Rutgers et al., 2004). Studies on attachment inmentally retarded children are scarce. However,

    Vaughn and his colleagues (Vaughn et al., 1994) found

    an overrepresentation of disorganized attachment in

    children with Down syndrome.

    Furthermore, in an exploratory way (due to the

    small number of children), we investigate whether the

    SSP produces the same physiological responses in

    children with autism as in children with other devel-

    opmental disorders. Based on studies conducted so far,

    we also expect overall higher responses in children

    with insecure attachments compared to children who

    are securely attached. In particular for children with a

    disorganized attachment relationship a higher cortisol

    response is expected. However, based on earlier find-

    ings (Jansen et al., 1999), we expect overall dampened

    cortisol responses in the group of children with ASD

    compared to the other groups.

    Disorganized attachment is also expected to be

    related to increased heart rate reactivity during re-

    union with the parent after a short separation. Based

    on the findings of Sigman et al. (2003) that children

    with autism show less cardiac response to parental

    separation and reunion, we will investigate whether

    increased heart rate reactivity in children with autism is

    related to disorganization of attachment, regardless of

    the autistic disorder.

    In sum, we investigate the distribution of attachment

    classifications as well as the childrens physiological

    responses as expressed in cortisol response and heart

    rate during the Strange Situation in young children

    with autism and other developmental disorders. The

    outcome of the combined behavioral data of the SSP

    with physiological measurements may contribute to a

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    better understanding of the social interactions of

    the children with autism at an early stage in their

    development.

    Method

    Participants

    All children were recruited from a population based

    sample around 30,000 children at the age of

    14 months, participating in a large screening study in

    a geographical defined area, the province of Utrecht

    (The Netherlands) for early detection for social

    developmental disorders. Details about the screening

    are described by Willemsen-Swinkels (Willemsen-

    Swinkels, Dietz, van Daalen, van Engeland, &

    Buitelaar, 2006) and Dietz (Dietz, Willemsen-Swin-

    kels, van Daalen, van Engeland, & Buitelaar, 2006).

    Children who were screen-positive for social devel-opmental delay were invited for further investigations

    at the Department of Child and Adolescent Psychia-

    try in Utrecht. The study design and screening pro-

    cedure were approved by the Medical Ethics Review

    Board of the University Medical Centre Utrecht.

    More information about the percentage of children

    who were found screen positive, and the percentages

    of children who received a final diagnosis of ASD, is

    presented in Dietz et al. (2006).

    Diagnostic Groups

    Children who were classified with AD (Autistic Dis-

    order), PDDNOS (Pervasive Developmental Level,

    not otherwise specified), MR (Mental Retardation) or

    LD (Language Disorder) at the appropriate age of

    42 months were included in the analyses. Children with

    other diagnosis were excluded from the analyses. As a

    result, data of 62 children with a developmental

    disorder were available. The children were divided

    across the four groups as follows; AD (n = 20), PDD-

    NOS (n = 14), MR (n = 12), and LD (n = 16), with an

    overall mean age of 27.65 months (SD = 6.04). The

    developmental level, as measured by the Mullen

    Scales, of the children with AD was 53.55 (SD = 3.66)

    and the developmental level of the group of children

    with MR 56.42 (SD = 5.52). The developmental level

    of the group with LD was 81.63 (SD = 10.39). The

    group of children with PDDNOS showed a wide range

    in developmental level, with some of these children

    having a mental handicap, and others functioning at a

    normal developmental level. Because the develop-

    mental level as well as the intensity of the autistic

    disorder might influence the attachment relationship,

    the group was further subdivided into the following

    groups: children with PDDNOS with concurrent

    mental retardation (PDDNOS mr, n = 6) develop-

    mental level 57.33 (SD = 5.43), and children with

    PDDNOS without concurrent mental retardation

    (PDDNOS not mr, n = 8) developmental level 86.38

    (SD = 14.83).For some analyses, a further contrast was formed of

    children with Autism Spectrum Disorders (ASD;

    n = 34; mean age 29.79, SD = 5.32) which included

    children with AD and children with PDDNOS, versus

    children without Autism Spectrum Disorder (non-

    ASD; n = 28; mean age 25.04, SD = 5.92) which

    included children with MR and children with LD. The

    developmental level of the children with ASD was

    61.94 (SD = 15.82) and the developmental level of the

    group of children without ASD 70.82 (SD = 15.29).

    We also included a control group (C). Control group

    children were screen negative on the ESAT (EarlyScreening of Autism Traits questionnaire), and based

    on parental reports and observations of the psycholo-

    gists these children were free from any child psychiatric

    disorder. To obtain this control group (n = 18; mean

    age 28.11 months, SD = 1.71; developmental level

    98.39, SD = 11.49), parents were contacted through

    well-baby clinics (see Dietz et al., in prep). Parents

    who agreed to participate were interviewed about the

    childs social and cognitive development at home.

    The control group children were also tested for

    developmental level with the Mullen Scales. Descrip-

    tive characteristics of the children are presented in

    Table 2.

    Procedure

    Psychiatric examinations included a series of five visits

    that were scheduled within a period of 5 weeks. At

    each weekly visit, the social and communicative

    behavior of the child was observed in a small group of

    young children and their parents. The assessments

    included a standardized parental interview, develop-

    mental history, and the Vineland Social-Emotional

    Early Childhood Scales (Sparrow, Balla, & Cicchetti,

    1997); standardized behavior observation (Autism

    Diagnostic Observation Schedule ADOS-G, (DiLavore,

    Lord, & Rutter, 2000), and pediatric examination and

    medical work-up. The cognitive level (developmental

    level) of the child was measured with the Mullen Scales

    of Early Learning (Mullen, 1995). The developmental

    level referred to in this paper is the early learning

    composite score, which is comparable to the develop-

    mental quotient (M = 100, SD = 15).

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    At age 42 months the child was re-examined, and

    apart from the earlier described measurement, the

    ADI-R (Lord, Rutter, & LeCouteur, 1994) parental

    interview was used. On the basis of all available

    information, and on the basis of clinical judgment, a

    diagnosis was given by an experienced child psychia-

    trist. The inter-rater reliability for the clinical diagnosis

    among three child psychiatrists (HvE, JB, ED) wascalculated first for two diagnostic categories; ASD or

    other than ASD. Agreement was reached in 92%

    (n = 38). Agreement corrected for chance was .74

    (Cohens Kappa). Second, the inter-rater reliability

    was determined for all diagnostic categories. An

    agreement was reached of 79% (n = 38), Cohens

    Kappa = .67. Diagnostic discrepancies were discussed

    to consensus. More details on the psychiatric diagnoses

    will be reported elsewhere (Van Daalen et al., in

    prep). The reliability rates are comparable with the

    studies of Stone and colleagues (Stone et al., 1999) and

    Fombonne (Fombonne et al., 2004) for reliability indiagnosing autism in very young children.

    The SSP took place at the Department of Child and

    Adolescent Psychiatry in Utrecht, in the presence of

    the primary caregiver of the child. The session was

    scheduled during the second of six visits at the hospital,

    which usually took 75 min, with the SSP at the begin-

    ning of the visit. After the SSP several structured tasks

    and unstructured play situations were observed. Dur-

    ing this visit, salivary cortisol and heart rate data were

    collected.

    Measures

    Strange Situation Procedure

    Ainsworth (Ainsworth et al., 1978) developed the SSP

    to observe the attachment behavior of the child to-

    wards the mother. The SSP contains two separations

    and two reunions with the primary caregiver. During

    this procedure the balance between seeking comfort

    with the attachment figure and exploration of the

    environment is assessed. Securely attached children

    show a balance in their proximity seeking and explo-

    ration of the environment, whereas avoidant children

    minimize their expression of negative emotions and

    ambivalent children maximize this expression. These

    children may remain passively or angrily focused on

    their parents even when the environment calls for

    exploration and play (Main, 1990). Nevertheless, these

    three organized strategies A (insecure-avoidant), B

    (secure) and C (insecure-resistant; Ainsworth et al.,

    1978) may be considered as adaptive to the infants

    environment, and each is supposed to allow for aTable

    2

    Characteristicsandattachmentdistributionsoftheclinicalandcontrolchildren(n=80)

    AD

    PDDNOS

    withmr

    PDDNOS

    withoutmr

    PDDNOS

    MR

    L

    D

    C

    ASD

    NASD

    M

    (SD

    )

    M

    (SD)

    M

    (SD)

    M

    (SD)

    M

    (SD)

    M

    (SD)

    M

    (SD)

    M

    (SD

    )

    M

    (SD)

    Total

    20

    6

    8

    14

    12

    1

    6

    18

    34

    28

    Boy/Girl

    15/5

    5/1

    7/1

    12/2

    8/4

    1

    5/1

    7/11

    27/7

    23/12

    Age

    30.2

    0(4.9

    6)

    27.0

    0(6.4

    5)

    30.8

    8(5.3

    6)

    29.2

    1(5.9

    5)

    24.5

    0(5.8

    5)

    2

    5.4

    4(6.1

    2)

    28.1

    1(1.7

    1)

    29.7

    9(

    5.3

    2)

    25.0

    4(5.9

    2)

    Developmentallevel

    53.5

    5(3.6

    6)

    57.3

    3(5.4

    3)

    86.3

    8(14.8

    3)

    73.9

    3(18.7

    7)

    56.4

    2(5.5

    2)

    8

    1.6

    3(10.3

    9)

    98.3

    9(11.4

    9)

    61.9

    4(

    15.8

    2)

    70.8

    2(15.2

    9)

    Autisticsymptoms

    33.2

    2(9.4

    2)

    32.1

    7(12.0

    1)

    13.2

    5(14.1

    6)

    21.3

    6(16.0

    6)

    19.0

    0(12.6

    3)

    1

    1.3

    8(5.7

    1)

    28.3

    2(

    13.7

    0)

    14.6

    4(9.9

    0)

    Attachment

    n(%)

    n(%)

    n(%)

    n(%)

    n(%)

    n

    (%)

    n(%)

    Insecureavoidant(A)

    3(15%

    )

    2(33.3

    %)

    1(12.5

    %)

    3(21.4

    %)

    2(16.7

    %)

    1

    (6.2

    5%)

    0(0%)

    6

    3

    Secure(B)

    7(35%

    )

    2(33.3

    %)

    4(50%)

    6(42.9

    %)

    4(33.3

    %)

    1

    1(68.8

    %)

    15(83%)

    13

    15

    Insecureresistant(C)

    0(0%)

    1(16.7

    %)

    1(12.5

    %)

    2(14.4

    %)

    2(16.7

    %)

    1

    (6.2

    5%)

    3(16.7

    %)

    2

    4

    Disorganized(D)

    10(50%)

    1(16.7

    %)

    2(25%)

    3(21.4

    %)

    4(33.3

    %)

    3

    (18.8

    %)

    0(0%)

    13

    3

    Heartrateanalysis

    8

    3

    4

    5

    3

    Age

    29.7

    5(4.4

    3)

    26.3

    3(5.0

    3)

    22.5

    0(7.6

    8)

    2

    5.0

    0(5.9

    2)

    29.0

    0(1.7

    3)

    Developmentallevel

    54.7

    5(4.4

    3)

    68.3

    3(9.2

    9)

    56.5

    0(6.8

    1)

    8

    4.0

    0(7.0

    0)

    99.3

    3(11.0

    2)

    AutisticSymptoms

    31.2

    5(9.6

    5)

    34.0

    0(3.0

    0)

    25.5

    0(13.3

    8)

    8

    .80(4.1

    5)

    Cortisolanalysis

    19

    8

    12

    1

    2

    17

    Age

    30.3

    7(5.0

    4)

    27.5

    0(5.0

    1)

    24.5

    0(5.8

    5)

    2

    5.0

    8(5.6

    2)

    28.1

    2(1.7

    4)

    Developmentallevel

    53.6

    8(3.7

    1)

    75.2

    5(19.4

    6)

    56.4

    2(5.5

    2)

    8

    2.1

    7(10.1

    6)

    98.7

    6(11.7

    2)

    AutisticSymptoms

    32.8

    4(9.5

    4)

    26.2

    5(14.5

    4)

    19.0

    0(12.6

    3)

    1

    0.6

    7(5.2

    6)

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    maximum of proximity to the specific attachment

    figure whose behavior to stress or distress is anticipated

    (Main, 1990). Disorganized attachment on the other

    hand, can be described as the breakdown of an other-

    wise consistent and organized strategy of emotion

    regulation (Main & Solomon, 1990; Van IJzendoorn

    et al., 1999).

    The SSP was coded by two trained and appropri-ately certified observers (SWS & MBK), who were

    unaware of the diagnoses of the children. The infants

    patterns of attachment behavior were classified as

    secure (B), insecure-avoidant (A), insecure-resistant(C)

    or disorganized (D) after taking baseline behavior of

    the children into account. Based on 28 ad random cases

    from this study, agreement for the four attachment

    classifications corrected for chance was .74 (Cohens

    Kappa). Besides the attachment classifications, we also

    used the simplified Richters, Waters and Vaughn

    (1988) algorithm to compute continuous scores for

    attachment security (Van IJzendoorn, & Kroonenberg,1990) on the basis of the interactive SSP scale scores

    for proximity seeking, contact maintaining, resistance

    and avoidance. Richters et al. (1988) developed

    classification functions to objectively classify infants

    attachments only on the basis of the interactive scales

    (proximity seeking, contact maintaining, resistance,

    and avoidance) and crying behavior in the two Strange

    Situation reunion episodes. The simplified and revised

    Richters et al. functions (i.e. without crying) appeared

    to have good agreement with the original classifications

    (Van IJzendoorn & Kroonenberg, 1990). Therefore,

    this simplified algorithm was used as a continuous

    measure of attachment security, with higher scores

    indicating more secure attachment.

    Disorganized attachment was coded using the Main

    and Solomon (1990) 9-point coding system for disor-

    ganized/disoriented attachment. As in our previous

    study on attachment in children with autistic disorders

    (Willemsen-Swinkels et al., 2000), the childs baseline

    behavior during the preseparation episodes of the SSP

    was taken into account when a score for disorganiza-

    tion was assigned. Intercoder reliability was .77

    (Pearsons correlation coefficient) for the security

    scale, and .66 (Pearsons correlation coefficient) for the

    disorganization scale (n = 28).

    Severity of Autistic Symptoms

    To quantify the severity of autistic symptoms, the raw

    data of the ADOS, collected during the first visit to the

    hospital, were used. This instrument, according to Lord

    (Lord, Leventhal, & Cook, 2001), offers the opportu-

    nity to quantify deficits across the autism spectrum,

    controlling for effects of language and cognitive delay,

    in individuals with significant impairments. It is sug-

    gested that quantitative measures of social reciprocity

    and repetitive behaviors and interests, with separate

    quantification of expressive language level and non-

    verbal intelligence, most accurately reflect the range of

    behavioral phenotypes in autism spectrum disorders

    (Lord et al., 2001). However, the ADOS module usedin the project was based on children who were 4 years

    of age and older. In our study we included younger

    children, and the algorithm was therefore not useful for

    our sample. Hence, the total sum score of ADOS

    module I, (the ADOS for children with little to no

    speech) reflects the range of behavioral phenotypes

    and was used in this study as a continuous score for

    intensity of autism (number of autistic symptoms).

    Following the ADOS algorithm, value 3 was recoded

    into value 2 before analyzing. ADOS scores of all

    clinical groups are presented in Table 2. The inter-

    rater reliability for the ADOS among a child psychia-trist and two psychologists was estimated on the basis

    of 6 random cases. The percentage of agreement, after

    code 3 was recoded to 2, was 97% for total sum score.

    Agreement corrected for chance was .62 (Cohens

    Kappa).

    Physiological Measurements

    Salivary Cortisol

    Saliva samples were collected before the SSP started

    and 25 min after the first separation, in order to

    examine the stress response of the children. To collect

    the saliva, a sterile cotton role was used to scrape along

    the childs inner cheek and under the tongue to absorb

    saliva. No oral stimulants (such as Kool-Acid crystals)

    were used. Saliva samples were stored frozen at 20C

    until analysis. The salivary cortisol concentrations were

    measured using a competitive radio-immuno-assay

    with antibody according to the new method that measures

    small quantities of cortisol in a reliable manner

    (De Weerth, Graat, Buitelaar, & Thijssen, 2003).

    Of the children participating in the cortisol response

    analyses, data of 68 children with two successful col-

    lected cortisol samples (one before and one after the

    SSP) were available. The other children either refused

    to participate in the physiological part of the study

    (n = 10; AD (n = 1), PDDNOS (n = 6), LD (n = 2),

    C (n = 1)) or one or both saliva samples were not

    successfully collected (n = 2; LD (n = 2)). The differ-

    ence between cortisol collected before and after the

    SSP was used as the value of cortisol response for each

    child. These values were used to analyze differences in

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    cortisol response between the different groups of

    children, taking the basal cortisol level of the children

    into account.

    Heart Rate

    During the session, the heart rate of the child was re-

    corded with the Sport Tester Polar Vantage NV (PolarElectrode KY, Finland; Treiber et al., 1989). The

    transmitter of the wireless portable monitor was

    attached to the chest of the child with sticky electrodes.

    The tester was programmed to record and score inter-

    beat intervals (IBIs) that were calculated for every 5-s

    interval. We used the BPM (beats per minute) for

    every 5 s of the last minute of separation and the first

    minute of the second reunion episode of the SSP. The

    mean heart rate was calculated for each of these peri-

    ods. Changes in mean heart rate around reunion were

    calculated subtracting the average heart rate of the

    minute before the reunion from the average heart rateof the minute after reunion. Reduction of stress after

    the reunion will result in lower heart rate and a nega-

    tive value of the heart rate reactivity; an increase of

    heart rate after reunion with the mother will be

    reflected in a positive value of the heart rate reactivity.

    The analyses were based on the second reunion of the

    procedure in order to examine heart rate reactivity in

    the most stressful condition.

    The registration of the heart rate was successful for

    23 children (AD (n = 8), PDDNOS (n = 3), MR

    (n = 4), LD (n = 5), C (n = 3)). The other children

    either refused to wear the heart rate monitor or dis-

    lodged it. They touched and pulled the heart rate

    monitor during the reunion episode, resulting in

    unreliable data. However, no systematic differences on

    age of the child, developmental level, number of

    autistic characteristics, security and disorganization of

    attachment were found between these children and

    children who did not refuse cooperation, neither in the

    total group nor in the group of children with ASD.

    Data Analyses

    Distribution of Attachment Classifications

    The distribution of attachment classifications was

    analyzed using the v2-test. First, an overall group

    comparison was performed including the control

    group. Also, the clinical groups were compared. Two

    normative attachment classification distributions,

    based on meta-analyses of attachment classifications

    for the normal western population and for the clinical

    population (Van IJzendoorn et al., 1999), were used

    as comparison groups. Contrast analyses were per-

    formed to distinguish between autistic symptoms and

    developmental level, as well as between attachment

    classifications.

    Cortisol Analyses

    We first examined whether a difference in cortisolresponse was detected among the various diagnostic

    groups. The analyses were followed by contrast anal-

    yses between children with and without a clinical

    diagnosis and children with and without ASD. The

    differences in cortisol response were analyzed using

    univariate analyses, taking the basal cortisol level into

    account as a covariate.

    Hierarchical Multivariate Regression Analyses

    To investigate the contribution of both developmental

    level and intensity of the autistic disorder to attach-ment, the continuous scores for attachment security

    and disorganization of the children were used in mul-

    tiple hierarchical regression analyses. Developmental

    level was entered as first predictor, in order to examine

    whether number of autistic symptoms contributed to

    security or disorganization after the difference in

    developmental level was taken into account. The total

    score of the ADOS module 1 was used as a measure-

    ment of intensity of autism (number of autistic symp-

    toms). The Mullen Scale of Early Learning (Mullen,

    1995) was used as index for the level of cognitive

    development of the child. For four clinical children, nooverall scores of the number of autistic symptoms were

    available, due to difficulties during participation in the

    ADOS. For the control group, no ADOS data were

    available either. As a result, data of 58 children with

    clinical diagnoses were used in these analyses.

    Two hierarchical multivariate regression analyses

    were performed to analyze the differences in cortisol

    response with basal cortisol level, developmental level,

    number of autistic symptoms and, in order, attachment

    security and disorganization as predictors (n = 58).

    Due to high correlations between basal level of cortisol

    and cortisol response, a residual of cortisol response

    was calculated, taking basal level of cortisol into

    account. Number of autistic symptoms and level of

    development were also correlated. Therefore, a resid-

    ual of the number of autistic symptoms was calculated,

    taking developmental level into account. We expected

    that attachment disorganization in particular would

    predict elevation of cortisol.

    It was also expected that attachment disorganization

    would predict an increase of heart rate at the reunion

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    with the mother. Therefore, a regression analysis with

    number of autistic symptoms (taking into account

    developmental level) and disorganization as predictors

    was performed on mean heart rate values (n = 20).

    Results

    Preliminary Analyses

    In a preliminary analysis, the KolmogorovSmirnov

    test was used to analyze the distribution of heart rate

    and of cortisol values, which revealed normal distri-

    butions. Not all children were tested on the same time

    of day. The sessions were divided over the day in 4

    parts; 9:15 am, 10:45 am, 13:15 pm and 14:45 pm. Most

    children were tested at 9 am (n = 28) and 10:30 am

    (n = 19). Ten children participated at 13:15 pm and ten

    children participated at 14:45 pm. To test the influence

    of time on the first salivary cortisol values, apreliminary analysis for first cortisol values was

    performed. Analysis of variance (ANOVA) showed

    that there were no effects of time F (3, 67) = 1.85,

    P = .13. No differences in cortisol response of boys and

    girls were found.

    Distribution of Attachment Classifications

    Table 2 shows the distribution of attachment classifi-

    cations for the various groups. The overall group

    comparison revealed a difference in distributions of

    attachment classifications, v2 (12, n = 80) = 24.35,P = .05. The main difference was found between chil-

    dren with and without a clinical diagnosis. Children

    with a developmental disorder were less often securely

    attached than comparisons without a developmental

    disorder.

    The distribution of our combined clinical groups was

    not significantly different from the combined clinical

    samples (clinical population, CP) of the meta-analysis

    of Van IJzendoorn and colleagues (Van IJzendoorn

    et al., 1999), and neither did our control group differ

    from the normal western population (NWP) in that

    meta-analysis.

    The distribution of secure and insecure attachments

    in the clinical versus control groups showed a signifi-

    cant difference, v2 (1, n = 80) = 8.18, P < .01, but no

    differences were detected for the distribution of secure

    versus insecure classifications in the ASD group com-

    pared to the non-ASD group. In the clinical groups,

    insecure attachments were over-represented. All clin-

    ical groups, except for LD, showed differences in

    distribution of secure versus insecure attachments

    compared with the control group; AD versus C v2

    (1, n = 38) = 9.08, P < 0.01; PDDNOS versus C v2

    (1, n = 32) = 5.72, P = 0.02; and MR versus C

    v2 (1, n = 30) = 7.75, P < 0.01. No differences in the

    distributions of attachment security were detected

    between AD and PDDNOS, between AD and MR,

    and between PDDNOS and LD. Children with more

    autistic symptoms or mental retardation were lessoften securely attached than the comparisons.

    The disorganized attachment classification was

    overrepresented in the clinical groups, v2 (1, n = 80)

    = 7.74, P < .01. The percentage of disorganized

    attachments in the ASD group was not different from

    that in the non-ASD group. The analyses for AD

    revealed differences with the control group, v2

    (1, n = 38) = 12.21, P < 0.01. The group with AD was

    not different from either the PDDNOS group or the

    MR group with respect to disorganized attachment.

    Each of the other clinical groups also differed from the

    control group; PDDNOS versus C, v2 (1, n = 32) =4.26, P = 0.04; MR versus C, v2 (1, n = 30) = 6.92,

    P < 0.01; and the group of LD versus C, v2 (1, n =

    34) = 3.70, P = 0.05. Attachment disorganization was

    overrepresented in each of the clinical groups com-

    pared to the control group.

    Is Attachment Security Associated with

    Developmental Level and Autistic Symptoms?

    Hierarchical regression was employed to determine

    whether developmental level or number of autistic

    symptoms predicted the development of secure

    attachment (continuous attachment security score).

    Table 3 displays the correlation between the vari-

    ables, the unstandardized regression coefficients (B)

    and intercept, the standardized regression coefficients

    (b), R, and R2 after entry of both variables: develop-

    mental level and number of autistic symptoms. In the

    first step developmental level did not contribute

    significantly to the prediction of attachment security. In

    step two, adding number of autistic symptoms to the

    equation, we found a significant regression for attach-

    ment security, F (2, 57) = 3.87, P = 0.03, explaining

    12% of the variance. More autistic symptoms predicted

    less attachment security, even after differences in

    developmental level were controlled for.

    We also employed a hierarchical regression analysis

    to determine the influence of developmental level and

    number of autistic symptoms on disorganized attach-

    ment. Table 4 shows that developmental level predicts

    the continuous score for disorganized attachment

    of the child. In the first step with developmental level

    as predictor, 9% of the variance is explained,

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    F (1, 57) = 5.56, P = 0.02. In step 2, with number of

    autistic symptoms as predictor added to the equation,

    R2 did not significantly improve. Therefore, only

    developmental level significantly predicted disorgani-

    zation of attachment.

    Cortisol Responses

    The mean values of cortisol response (t2 t1) as well

    as the residuals of cortisol response after taking basal

    cortisol into account are shown in Table 5. Baseline

    cortisol and cortisol responsivity in reaction to stress

    were significantly correlated (r = .67, P = .00). Chil-

    dren who started with low basal cortisol values showed

    more response in cortisol than children who started

    with higher cortisol values (Fig. 1).

    Table 5 displays the mean values of cortisol

    response. Diagnostic groups did not differ in mean

    basal cortisol values (F (3, 50) = .74, P = .53). There

    was an overall significant main group effect in cortisol

    response, F (4, 68) = 3.20, P = .02 when basal cortisol

    was taken into account. Contrast analyses regardingthe clinical group versus the control group revealed a

    stronger response in the control group, F (1, 68)

    = 10.34, P < .01. However, the response of the control

    children was a decrease, and not an increase that would

    be indicative of stress induced by the separation and

    reunion with the caregiver. The contrast analysis of

    Table 4 Predictingattachment disorganization inchildren with developmentaldisorders (n = 58)

    *P < .05, **P < .01

    Correlation matrix Regression analyses

    Developmentallevel

    Autisticsymptoms

    B SE B b R R2

    Step 1 0.30 0.09Developmental level .06 .03 0.30*Step 2 0.34 0.12

    Developmental level 1.00 .04 .03 0.17Autistic symptoms 0.61** 1.00 .05 .04 0.21

    Table 5 Mean cortisol values and contrast analyses of residual cortisol response (n = 68)

    N AD PDDNOS MR LD CM (SD) M (SD) M (SD) M (SD) M (SD)19 8 12 12 17

    Residual cortisol response .35 (.83) .22 (.86) .27 (1.17) .19 (1.24) .62 .60Cortisol response .18 (2.58) .31 (1.90) .03 (4.98) .96 (3.87) .58 (1.78)Basal cortisol 9.65 (3.65) 8.23 (3.29) 9.58 (5.08) 7.68 (2.85) 7.11 (2.34)Contrast analyses cortisol response

    Mdif SE Mdif SE Mdif SE Mdif SE Mdif SE

    AD PDDNOS .58 (.40) MR .08 (.35) .49 (.43) LD .17 (.35) .41 (.43) .08 (.38) C .97 (.31)* .40 (.40) .89 (.35) .80 (.35)

    *P < 0.05, contrast analyses using Bonferoni-correction

    Table 3 Predictingattachment security inchildren with developmentaldisorders (n = 58)

    *P < .05, **P < .01

    Correlation matrix Regression analyses

    Developmentallevel

    Autisticsymptoms

    B SE B b R R2

    Step 1 0.23 0.05Developmental level .05 .03 0.23Step 2 0.35 0.12Developmental level 1.00 < .01 .04 0.02Autistic symptoms 0.61** 1.00 .09 .04 0.34*

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    children with AD versus control group also showed a

    significant difference, F(1, 36) = 10.60, P < .01. There

    were no differences between clinical children with and

    without ASD, F (1, 51) < .01, P = .93.

    Contrast analyses of cortisol response in clinical

    children with and without secure attachment did not

    reveal any difference, and neither showed childrenwith and without the disorganized attachment classifi-

    cation differences in cortisol response to the SSP.

    Due to high correlations between basal cortisol level

    and cortisol response, the residual of cortisol response

    was calculated, taking basal cortisol into account.

    Regression analyses for these residuals of cortisol

    response were performed to investigate whether

    number of autistic symptoms (with developmental le-

    vel taken into account) and attachment security or

    disorganization influenced cortisol response. Table 6

    displays the univariate correlations and results of the

    regression analyses. In the first step, number of autistic

    symptoms was entered into the equation, contributing

    significantly to the prediction of cortisol response, F(1, 48) = 6.50, P = 0.01, with 12% of the variance

    explained. In step 2 (Table 6, step 2a), security of

    attachment was entered into the equation. Although

    the equation was significant, F (2, 48) = 3.18, P = 0.05,

    R2 did not improve significantly. Therefore, only more

    autistic symptoms significantly predicted less cortisol

    response.

    In the second hierarchical regression disorganization

    of attachment rather than attachment security was

    entered as predictor at step 2. R2 did not significantly

    improve. Therefore, again only more autistic symp-

    toms significantly predicted less cortisol response(Table 6, step 2b).

    Heart Rate Variability

    Hierarchical regression was employed to determine

    whether the number of autistic symptoms (controlled

    for developmental level) and attachment disorganiza-

    tion predicted heart rate reactivity at the second

    reunion (Table 7). Of the 23 children with successful

    heart rate measures, 20 children were used in the

    regression analysis. Three children (from the controlgroup) had no administration of the number of autistic

    characteristics. The predictors were entered in two

    hierarchical steps. No significant equation was found in

    the first step, entering number of autistic symptoms. In

    step 2, a significant contribution of attachment disor-

    ganization to the regression equation predicted change

    basal cortisol

    3020100

    cortisolresponse

    10

    0

    -10

    -20

    non ASD

    ASD

    Fig. 1 Cortisol responses of children with and without ASD

    Table 6 Multiple hierarchical regression analysis on cortisol response (n = 48)

    Regression analyses

    Resid Autisticsymptoms

    Att. Securitydisorganization

    B SE B b R R2

    Step 1 .35 .12Resid Autistic symptoms .34 .13 .35*Step 2a (Att. Security) .35 .12Resid 1.00 .34 .14 .35*Autistic symptoms

    Attachment security.19 1.00 < .01 .04 < .01

    Step 2b (Disorganization) .42 .17Resid 1.00 -.29 .13 -.30*Autistic SymptomsDisorganization .22 1.00 .08 .05 .24

    *P < 0.05

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    in heart rate F(2, 19) = 2.70, P = 0.05, explaining 24%

    of the variability. Disorganized attachment was asso-

    ciated with more heart rate reactivity.

    Examining the association between cortisol re-

    sponse, autistic symptoms, and attachment disorgani-

    zation in the subgroup of children included in the heart

    rate analysis, we conducted a hierarchical regression

    analysis (Table 7). Characteristics of this subgroup

    (n = 20) are shown in Table 2. In the first step, number

    of autistic symptoms was entered into the equation,

    contributing significantly to the prediction of cortisol

    response, F (1, 19) = 9.41, P < 0.01, with 34% of the

    variance explained. Disorganization of attachment was

    entered into the equation in step 2. Although the

    equation was significant, F (2, 19) = 4.70, P = 0.03, R2

    did not improve significantly. Thus, more autistic

    symptoms significantly predicted less cortisol response,

    confirming the outcome in the larger sample.

    Discussion

    The distribution of attachment classifications in chil-

    dren with autistic spectrum disorders, other develop-

    mental disorders and a non-clinical comparison group

    was investigated. Contrast analyses of clinical groups

    versus a control group showed that lower rates ofsecure attachment and higher rates of disorganized

    attachment were found in the clinical groups. There

    were no differences in distributions of attachment

    classifications among the clinical groups. Further

    analyses showed that severity of autism was associated

    with less secure attachment, whereas lower intellectual

    capabilities increased the chance for disorganized

    attachment. The exploratory analyses regarding corti-

    sol responses revealed that basal cortisol values

    affected cortisol responsivity during the separation.

    Children who started with lower basal cortisol levels

    showed more responsivity than children with higher

    basal cortisol levels. Controlling for basal cortisol lev-

    els, more cortisol responsivity was predicted by fewer

    autistic symptoms. There was no contribution of

    (secure or disorganized) attachment to the prediction

    of cortisol responses. Children with disorganized

    attachment, however, showed more heart rate reac-

    tivity during the Strange Situation.

    Distribution of Attachment Classifications

    Children with autism are, despite their autistic char-

    acteristics, capable of forming attachment relationships

    with their caregivers. However, secure attachments

    were underrepresented in children with autism,

    whereas the percentage of disorganized attachment

    was higher compared to the normal population. Similar

    to Rutgers et al. (2004) meta-analytic results, the

    severity of the autistic disorder was a significant pre-

    dictor for the development of an insecure attachment

    relationship. It should be noted that our study on

    attachment in autism is the first with 2-year-old chil-

    dren.

    Children with autism have also been shown to dis-

    play more often disorganized attachment behavior(Capps et al., 1994; Willemsen-Swinkels et al., 2000).

    In the meta-analysis of Rutgers and colleagues

    (Rutgers et al., 2004), the issue of disorganized

    attachment was not addressed, due to the small num-

    ber of studies with autistic participants that included

    disorganized attachment. The two studies that did as-

    sess disorganized attachment found relatively high

    percentages of disorganization. However, most of these

    children were mentally retarded or showed at least

    Table 7 Multiple hierarchical regression analysis with autistic symptoms and disorganization for predicting heart rate (n = 20) andcortisol response (n = 20)

    Resid Autistic symptoms Disorganization B SE B b R R2

    Regression analysis heart rateStep 1 .04 < .01Resid Autistic symptoms -.40 2.70 -.04Step 2 .49 .24

    Resid Autistic symptoms 1.00 3.05 2.68 -.27Disorganization .43* 1.00 2.45 1.06 .54*1

    Regression analysis cortisolStep 1 .59 .34Resid Autistic symptoms -.72 .23 -.59**Step 2 .60 .36Resid Autistic symptoms 1.00 -.78 .26 -.64**Disorganization .43* 1.00 .06 .10 .13

    *P < .05, **P < .01; 1one-tailed

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    considerable delays in their mental development

    (Capps et al., 1994; Willemsen-Swinkels et al., 2000).

    The confounding effects of cognitive abilities and dis-

    organized attachment has therefore been an issue for

    debate.

    Lyons-Ruth and colleagues (Lyons-Ruth, Easter-

    brooks, & Cibelli, 1997; Lyons-Ruth, Repacholi,

    McLeod, & Silva, 1991) found that disorganizedattachment was related to lower mental capabilities.

    Vaughn et al. (1994) found that many children with

    Down syndrome were disorganized. Dissanayake and

    Crossley (1997) suggested that developmental level

    may influence the consistency of behavioral patterns,

    and thus might be associated with (dis-)organization of

    attachment. Associations between disorganized

    attachment and neuro-developmental vulnerabilities

    have also been reported (Green & Goldwyn, 2002). So,

    below a certain level cognitive abilities may play an

    important role in the classification of (disorganized)

    attachment. Children who do not really understandwhat happens during the separations and reunions with

    their parent may not experience stress, or they may

    become too confused, which may explain why mentally

    retarded children show more disorganized attachment

    behaviors compared to normally developing controls.

    In our study we found that children with autism as

    well as children with MR showed higher percentages of

    disorganized attachment. Unfortunately, all children

    with autism were also mentally retarded. But in con-

    trast to other studies, we were able to disentangle the

    influences of autistic symptoms and developmental

    level by regression analyses. Hierarchical regression

    analyses showed that disorganized attachment was

    mainly predicted by the developmental level of the

    children, regardless of their autistic symptoms. Mental

    retardation therefore appears to affect attachment

    disorganization or its assessment, and the increased

    level of disorganized behavior in children with autism

    may be associated with their being often mentally

    retarded as well (see Rutgers et al., 2004).

    These findings are partly in line with the theory of

    developmental delay (Rogers, Ozonoff, & Maslin-

    Cole, 1991). The construction of a working model of

    self and parent would be affected by the childs

    inability to interpret other peoples emotional cues or

    internal states (Rogers et al., 1993). A separation with

    the parent, like in the SSP, may not be interpreted as

    threatening. Sigman et al. (2003) found that children

    with autism had no inclination to orient themselves to

    the separation, which may indicate a lack of under-

    standing. However, whether this developmental delay

    may contribute to a delay in development of security of

    attachment remains unclear. To answer that question

    the children should be studied again at a later age, to

    investigate the development of their attachment rela-

    tionship. In sum, severity of autism is a strong predictor

    for the development of insecure attachment. More

    autistic characteristics enhance the risk for attachment

    insecurity. Developmental level is the strongest pre-

    dictor for disorganization of attachment. The lower

    the developmental level, the higher the risk for thechild to develop a disorganized attachment relation-

    ship, regardless of the developmental disorder of the

    child.

    Physiological Responses

    Disorganization of attachment is related to problem-

    atic stress management and problematic regulation of

    negative emotions (Van IJzendoorn et al., 1999). Ele-

    vations in cortisol level and heart rate variability are

    also related to stress. In this study we investigated the

    relation between disorganized attachment and physio-logical measurements in children with autism and other

    developmental disorders. Several studies on normally

    developing children reporting adrenocortical responses

    to the SSP showed elevated cortisol responses in chil-

    dren with a disorganized classification compared to

    children with organized attachment classifications

    (Nachmias et al., 1996; Spangler & Grossmann, 1993;

    Spangler & Scheubeck, 1993). This is in line with the

    suggestion that the neuroendocrine system is activated

    when coping strategies are inadequate or unavailable

    (Spangler & Grossmann, 1993), which indeed is the

    case in normally developing children who show dis-

    organized attachment (Hertsgaard et al., 1995). In the

    current study, we found that attachment disorganiza-

    tion did not contribute to differences in cortisol

    response. Security of attachment (as a continuous score

    based on the interactive behaviors in the SSP) did not

    contribute to the difference in cortisol response either.

    Controlling for mental development and basal cor-

    tisol, more autistic symptoms predicted a lower cortisol

    response. A blunted cortisol response in children with

    PDD was also found in the study of Jansen et al.

    (1999). These findings can also be interpreted as a lack

    of understanding of the situation, and thereby also

    partly support the developmental delay theory (Rogers

    et al, 1991).

    We found no differences in basal cortisol between

    children participating in the Strange Situation proce-

    dure at different times during the day, although we

    expected an effect of circadian rhythm. Under normal

    circumstances, infants develop a circadian rhythm

    during the first year of life, although the age of onset of

    this rhythm is still a matter of discussion (De Weerth,

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    Zijl & Buitelaar, 2003). The onset of this rhythm in

    children with a developmental disorder at this young

    age has not been investigated yet. Developmental

    disorders may be accompanied by delays in the

    development of the circadian rhythm, resulting in

    similar basal cortisol levels at different times in our

    group. Further research into stabilization of the circa-

    dian rhythm in toddlers with developmental disordersis needed. Another explanation might be that we did

    not take the emotional state of the child during the

    basal cortisol measurement into account. Some

    researchers have argued that expression of negative

    mood may release tension and thus reduce the activity

    of the HPA-axis (Ahnert, Gunnar, Lamb, & Barthel,

    2004; Lewis, Ramsey, & Kawakami, 1993).

    Elevated heart rate reactivity was found to be

    associated with disorganized attachment. This is in line

    with findings of Willemsen-Swinkels et al. (2000), who

    reported a difference in mean heart rate between

    children with ASD with and without disorganizedattachment during a separationreunion episode. It

    should be noted that we found more elevated heart

    rate in disorganized children after controlling for

    number of autistic symptoms and developmental level.

    Our study thus extends the earlier finding of a negative

    association between stress coping mechanisms and

    elevated heart rate, by showing that children with

    disorganized attachments display more heart rate

    reactivity regardless of their specific disorder. This

    provocative finding should be considered a hypothesis

    for further investigation into the stress regulation of

    disorganized children with clinical diagnoses. Disor-

    ganized attachment may lead to dysregulation of

    emotions during stress. Due to technical problems,

    however, only a small group of children willing to

    accept the sticky electrodes and the heart rate meter,

    was included in this analysis. This subgroup might be

    more advanced in their social or cognitive develop-

    ment as they accepted the burden of being tested more

    readily than the other children. Their advanced

    developmental status might explain the association

    between disorganization and stress reactivity, at least

    with respect to heart rate. However, no differences

    were detected in developmental level, age, number of

    autistic symptoms, security of attachment, or attach-

    ment disorganization between this subgroup and the

    total group of children participating in the cortisol

    analyses. Another explanation may be that there are

    different sub-types of the autistic spectrum disorder

    patterns among children with ASD. Depending on the

    specific sub-type, some children may be hypo-respon-

    sive, while others are hyper-responsive to various

    stressors (Greenspan & Wieder, 2005). Unfortunately,

    our group of children with ASD was too small to test

    this hypothesis.

    This is the first study on toddlers with autism,

    combining attachment and physiological data at this

    young age. Some limitations should be noted. The

    subgroups of children were rather small, in particular

    for the physiological part of the study. To understand

    more about the physiological responses in childrenwith developmental disorders, larger groups are

    required. Larger groups also create the possibility to

    differentiate between children with an insecure-avoi-

    dant and insecure-ambivalent attachment. However,

    collecting this kind of data, especially the heart rate

    data, is very complex in young children with develop-

    mental disorders. Perhaps the children need to be

    prepared for wearing electrodes by using dummy

    equipment. After getting used to the dummy, the real

    equipment may be accepted more easily. Larger groups

    would also create the opportunity to divide the groups

    of children in subgroups based on hypo- and hyper-responsivity. Second, not much is known about the

    stabilization of the circadian rhythm in children with

    developmental disorders like autism. We need more

    information on the circadian rhythm in clinical infants

    and toddlers for a more definite interpretation of

    our data. Third, there was no assessment of autistic

    characteristics in the control group; therefore control

    children could not be included in the regression

    analyses.

    Taken together, in this first study on attachment in

    2-year-old children with autism we found that severity

    of autism was associated with more attachment inse-

    curity, and mental retardation increased the chance for

    disorganized attachment. Cortisol responsivity

    decreased with the presence of more autistic symp-

    toms. No influences were detected for attachment

    security or disorganization. Nevertheless, in a small

    subgroup attachment disorganization was related to

    increased heart rate reactivity during the Strange Sit-

    uation procedure. The heart rate findings provide fur-

    ther physiological evidence for the validity of

    disorganized attachment in clinical groups, but the

    findings on cortisol also raise questions about the

    function of disorganized behaviors of children with

    autism in coping with stress, and about the interpre-

    tation of disorganized attachment behaviors in men-

    tally retarded children.

    Acknowledgments This research was funded in part by thefollowing grants: ZonMw Dutch Organisation for ScientificResearch (NWO), Grant for Cure Autism Now, and The Korc-zak Foundation. Marinus van IJzendoorn is supported by theNWO/SPINOZA Prize of the Netherlands Organization forScientific Research, and Marian J. Bakermans-Kranenburg by

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    a VIDI grant of the Netherlands Organization for ScientificResearch.

    References

    Ahnert, L., Gunnar, M. R., Lamb, M. E., & Barthel, M. (2004).Transition to child care: Associations with infant-motherattachment, infant negative emotion, and cortisol elevations.Child Development, 75, 639650.

    Ainsworth, M. D. S., Blehar, M. C., Waters, M. C., & Wall, S.(1978). Patterns of attachment. NJ Hillsdale: LaurenceErlbaum.

    American Psychiatric Association (1994). Diagnostic and Sta-tistical Manual of Mental Disorders, Washington DC.

    Baron-Cohen, S. (1995). The autistic childs theory of mind: Thecase of specific developmental delay. Journal of ClinicalChild Psychology and Psychiatry, 30, 285298.

    Buitelaar, J. K. (1995). Attachment and Social Withdrawal inAutism Hypotheses and Findings. Behaviour, 132, 319350.

    Cacioppo, J. T., & Berntson, G. G. (1992). Social Psychological

    Contributions to the Decade of the Brain - Doctrine ofMultilevel Analysis. American Psychologist, 47, 10191028.Capps, L., Sigman, M., & Mundy, P. (1994). Attachment Security

    in Children with Autism. Development and Psychopathol-ogy, 6, 249261.

    Cassidy, J. & Shaver. P. R. (1999). Handbook of Attachment:Theory, Research, and Clinical Applications. New York, NY:Guilford Publications.

    Corona, R., Dissanayake, C., Arbella, S., Wellington, P., & Sig-man, M. (1998). Is affect aversive to young children withautism? Behavioral and cardiac responses to experimentaldistress. Child Development, 69, 14941502.

    Dawson, G. & Lewy, A. (1989). Arousal, attention, and the so-cioemotional impairments of individuals with autism. In G.Dawson (Ed.), Autism: Nature, diagnosis, and treatment.

    New York: Guilford Press.De Weerth, C., Graat, G., Buitelaar, J. K., & Thijssen, J. H. H.(2003). Measurement of cortisol in small quantities of saliva.Clinical Chemistry, 49, 658660.

    De Weerth, C., Zijl, R. H., & Buitelaar, J. K. (2003). Develop-ment of cortisol circadian rhythm in infancy. Early HumanDevelopment, 73, 3952.

    Dietz, C., Willemsen, S. H. N., Daalen van E., Engeland van H.,& Buitelaar, J. K. (2006). Screening for autistic spectrumdisorders in children aged 14 to 15 months. II: Populationscreening with the Early Screening for Autistic Traits(ESAT) Questionnaire. Design and general findings. Jour-nal of Autism and Developmental Disorders. (in press).

    DiLavore, P. C., Lord, C., & Rutter, M. (2000). The pre-linguisticautism diagnostic observation schedule. Journal of Autism

    and Developmental Disorders, 25, 355379.Dissanayake, C., & Crossley, S. A. (1996). Proximity and soci-

    able behaviours in autism: Evidence for attachment. Journalof Child Psychology and Psychiatry and Allied Disciplines,37, 149156.

    Dissanayake, C., & Crossley, S. A. (1997). Autistic childrensresponses to separation and reunion with their mothers.Journal of Autism and Developmental Disorders, 27, 295312.

    Eisenberg, N., & Fabes, R. A. (1999). Emotion, regulation, andthe development of social competence. In S. C. Margeret(Ed.), Emotion and social behavior. Review of personalityand social psychology. Vol. 14 (pp. 119150). Newbury Park,CA: Sage.

    Fabes, R. A., Eisenberg, N., & Eisenbud, L., (1993). Behavioraland physiological correlates of childrens reactions to othersin distress. Developmental Psychology, 29, 655663.

    Fombonne, E., Heavey, L., Smeeth, L., Rodrigues, L. C., Cook,C., Smith, P. G., Meng, L. Y., & Hall, A. J. (2004). Vali-dation of the diagnosis of autism in general practitionerrecords. Bmc Public Health, 4.

    Green, J., & Goldwyn, R. (2002). Annotation: Attachment dis-organization and psychopathology: new findings in attach-ment research and their potential implications fordevelopmental psychopathology in childhood. Journal ofChild Psychology and Psychiatry and Allied Disciplines, 43,835846.

    Greenspan, S. I. & Wieder, S. (2005). Interdisciplinary Councilon Developmental and Learning Disorders DiagnosticManual for Infancy and Early Childhood (ICDL-DMIC).Bethesda, MD: ICDL.

    Gunnar, M. R., Mangelsdorf, S., Larson, M., & Hertsgaard, L.(1989). Attachment, Temperament, and AdrenocorticalActivity in Infancy A Study of Psychoendocrine Regula-tion. Developmental Psychology, 25, 355363.

    Gunnar, M. R., Brodersen, L., Nachmias, M., Buss, K., & Rig-atuso, J. (1996). Stress reactivity and attachment security.Developmental Psychobiology, 29, 191204.

    Hertsgaard, L., Gunnar, M., Erickson, M. F., & Nachmias, M.(1995). Adrenocortical Responses to the Strange Situationin Infants with Disorganized Disoriented AttachmentRelationships. Child Development, 66, 11001106.

    Hesse, E. (1999). The Adult Attachment Interview. In J. Cassidy& P. R. Shaver (Eds.) Handbook of Attachment, (pp. 399).

    Jansen, L. M. C., Gispen-de Wied, C. C., Jansen, M. A., van derGaag, R. J., Matthys, W., & van Engeland, H. (1999).Pituitary-adrenal reactivity in a child psychiatric population:salivary cortisol response to stressors. European Neuropsy-chopharmacology, 9, 6775.

    Kirschbaum, C., & Hellhammer, D. H. (1994) Salivary cortisol inpsychoneuroendocrine research recent developments andapplications. Psychoneuroendocrinology, 19, 313333.

    Lewis, M., Ramsay, D. S., & Kawakami, K. (1993). Differencesbetween Japanese infants and Caucasian American infantsin behavioral and cortisol responses to inoculation. ChildDevelopment, 64, 17721731.

    Lord, C., Rutter, M., & Le Couteur, A. (1994). Autism diagnosticinterview-revised: A revised version of a diagnostic inter-view for caregivers of individuals with possible pervasivedevelopmental disorders. Journal of Autism and Develop-mental Disorders, 24, 659685.

    Lord, C., Leventhal, B. L., & Cook, E. H. (2001). Quantifying thephenotype in autism spectrum disorders. American Journalof Medical Genetics, 105, 3638.

    Lyons-Ruth, K., Repacholi, B., McLeod, S., & Silva, E.(1991). Disorganized attachment behavior in infancy:Short-term stability, maternal and infant correlations, and

    risk-related subtypes. Development and Psychopathology,3, 377396.Lyons-Ruth, K., Easterbrooks, M. A., & Cibelli, C. D. (1997).

    Infant attachment strategies, infant mental lag, and maternaldepressive symptoms: Predictors of internalizing problemsat age 7. Developmental Psychology, 33, 681692.

    Main, M. & Solomon, J. (1986). Discovery of an insecure-dis-organizid/disoriented attachment pattern. In T. B. Bazelton& M. W. Yogman (Eds.) Affective development in infancy.(pp. 95124). Norwood, NJ: Ablex,.

    Main, M. & Solomon, J. (1990). Procedures for identifyinginfants as disorganized/disoriented during the Ainsworthstrange Situation. In M. T. Greenberg, D. Cicchetti & E. M.

    J Autism Dev Disord (2007) 37:11231138 1137

    123

  • 7/27/2019 Apego en Autismo y Otros Transtornos

    16/16

    Cummings (Eds.) Attachment in preschool years: Theory,research and intervention. (pp. 121160). Chicago and Lon-don: University of Chicago press.

    Main, M. (1990). Cross-cultural studies of attachment organiza-tion recent studies, changing methodologies, and theconcept of conditional strategies. Human Development, 33,4861.

    McEwen, B. S., & Sapolsky, R. M. (1995). Stress and cognitivefunction. Current Opinion in Neurobiology, 5, 205216.

    Mullen, E. M. Mullen Scales of Early Learning. (1995). CirclePines, MN: American Guidance Services, Inc.

    Nachmias, M., Gunnar, M., Mangelsdorf, S., Parritz, R. H., &Buss, K. (1996). Behavioral inhibition and stress reactivity:The moderating role of attachment security. Child Devel-opment, 67, 508522.

    Pipp-Siegel, S., Siegel, C. H., & Dean, J. (1999). Neurologicalaspects of the disorganized/disoriented attachment classifi-cation system: Differentiating quality of the attachmentrelationship from neurological impairment. Monographs ofthe Society for Research in Child Development, 64, 25.

    Richters, J. E., Waters, E., & Vaughn, B. E. (1988). Empiricalclassification of infantmother relationships from interactivebehavior and crying during reunion. Child Development, 59,512522.

    Rogers, S. J., Ozonoff, S., Maslin-Cole, C. (1991). A comparativestudy of attachment behavior in young children with autismor other developmental disorders. Journal of AmericanAcademy of Child and Adolescent Psychiatry, 30, 483.

    Rogers, S. J., Ozonoff, S., Maslin-Cole, C. (1993). Develop-mental aspects of attachment behavior in young childrenwith pervasive developmental disorders. Journal of Ameri-can Academy of Child and Adolescent Psychiatry, 32, 12741282.

    Rutgers, A. H., Bakermans-Kranenburg, M. J., van IJzendoorn,M. H., & Berckelaer-Onnes, I. A. (2004). Autism andattachment: A meta-analytic review. Journal of Child Psy-chology and Psychiatry, 45, 11231134.

    Rutter, M. (1978). Diagnosis and definition of childhood autism.

    Journal of Autism and Childhood Schizophrenia, 8, 139161.Sigman, M., Dissanayake, C., Corona, R., Espinosa, M., (2003).Social and cardiac responses of young children with autism.Autism, 7, 205216.

    Sigman, M., & Ungerer, J. A. (1984). Attachment behaviors inautistic-children. Journal of Autism and DevelopmentalDisorders, 14, 231244.

    Spangler, G., & Grossmann, K. E. (1993). Biobehavioral orga-nization in securely and insecurely attached infants. ChildDevelopment, 64, 14391450.

    Spangler, G., & Scheubeck, R. (1993). Behavioral organization innewborns and its relation to adrenocortical and cardiacactivity. Child Development, 64, 622633.

    Spangler, G., & Schieche, M. (1998). Emotional and adreno-cortical responses of infants to the strange situation: Thedifferential function of emotional expression. InternationalJournal of Behavioral Development, 22, 681706.

    Sparrow, S. S., Balla, D. A., & Cicchetti, D. V. (1997). VinelandSocial-Emotional Early Childhood Scales: Manual. CirclePines MC, American Guidance Service. .

    Stern, D. (1985). The interpersonal world of the infant. NewYork: basic Books.

    Stone, W. L., Lee, E. B., Ashford, L., Brissie, J., Hepburn, S. L.,Coonrod, E. E., & Weiss, B. H. (1999). Can autism bediagnosed accurately in children under 3 years? Journal ofChild Psychology and Psychiatry and Allied Disciplines, 40,219226.

    Treiber, F. A., Musante, L., Hartdagan, S., Davis, H., Levy, M.,& Strong, W. B. (1989). Validation of a heart-rate monitorwith children in laboratory and field settings. Medicine andScience in Sports and Exercise, 21, 338342.

    Van IJzendoorn, M. H., & Kroonenberg, P. M. (1990). Cross-cultural consistancy of coding the strange situation. InfantBehavior and Development, 13, 469485.

    Van IJzendoorn, M. H., Schuengel, C., & Bakermans-Kranen-burg, M. J. (1999). Disorganized attachment in early child-hood: Meta-analysis of precursors, concomitants, andsequelae. Development and Psychopathology, 11, 225249.

    Vaughn, B. E., Goldberg, S., Atkinson, L., Marcovitch, S.,Macgregor, D., & Seifer, R. (1994). Quality of toddlermother attachment in children with Down-Syndrome limits to interpretation of strange situation behavior. ChildDevelopment, 65, 95108.

    Volkmar, F. R., Sparrow, S. S., Goudreau, D., Cicchetti, D. V.,Paul, R., & Cohen, D. J. (1987). Social deficits in autism anoperational approach using the vineland adaptive-behaviorscales. Journal of the American Academy of Child andAdolescent Psychiatry, 26, 156161.

    Willemsen-Swinkels, S. H. N., Bakermans-Kranenburg, M. J.,Buitelaar, J. K., van IJzendoorn, M. H., & van Engeland, H.(2000). Insecure and disorganised attachment in children

    with a pervasive developmental disorder: Relationship withsocial interaction and heart rate. Journal of Child Psychol-ogy and Psychiatry and Allied Disciplines, 41, 759767.

    Willemsen-Swinkels, S. H. N, Dietz, C., Daalen van E., Kerkhof,I., Engeland van H.,& Buitelaar, J. K. (2006). Screening forautistic spectrum disorders in children aged 14 to 15 months.I. The development of the Early Screening for AutisticTraits Questionnaire. Journal of Autism and DevelopmentalDisorders. (in press).

    1138 J Autism Dev Disord (2007) 37:11231138

    123