Describes the Autism Diagnostic Interview-Revised (ADI-R), a revision of the Autism Diagnostic Interview, a semistructured, investigator-based interview for caregivers of children and adults for whom autism or pervasive developmental disorders is a possible diagnosis. The revised interview has been reorganized, shortened, modified to be appropriate for children with mental ages from about 18 months into adulthood and linked to ICD-10 and DSM-IV criteria. Psychometric data are presented for a sample of preschool children.

Autism Diagnostic Interview-Revised: a revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders

The Autism Diagnostic Observation Schedule-Generic (ADOS-G) is a semistructured, standardized assessment of social interaction, communication, play, and imaginative use of materials for individuals suspected of having autism spectrum disorders. The observational schedule consists of four 30-minute modules, each designed to be administered to different individuals according to their level of expressive language. Psychometric data are presented for 223 children and adults with Autistic Disorder (autism), Pervasive Developmental Disorder Not Otherwise Specified (PDDNOS) or nonspectrum diagnoses. Within each module, diagnostic groups were equivalent on expressive language level. Results indicate substantial interrater and test-retest reliability for individual items, excellent interrater reliability within domains and excellent internal consistency. Comparisons of means indicated consistent differentiation of autism and PDDNOS from nonspectrum individuals, with some, but less consistent, differentiation of autism from PDDNOS. A priori operationalization of DSM-IV/ICD-10 criteria, factor analyses, and ROC curves were used to generate diagnostic algorithms with thresholds set for autism and broader autism spectrum/PDD. Algorithm sensitivities and specificities for autism and PDDNOS relative to nonspectrum disorders were excellent, with moderate differentiation of autism from PDDNOS.

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The autism diagnostic observation schedule-generic: a standard measure of social and communication deficits associated with the spectrum of autism.

Currently there are no brief, self-administered instruments for measuring the degree to which an adult with normal intelligence has the traits associated with the autistic spectrum. In this paper, we report on a new instrument to assess this: the Autism-Spectrum Quotient (AQ). Individuals score in the range 0-50. Four groups of subjects were assessed: Group 1: 58 adults with Asperger syndrome (AS) or high-functioning autism (HFA); Group 2: 174 randomly selected controls. Group 3: 840 students in Cambridge University; and Group 4: 16 winners of the UK Mathematics Olympiad. The adults with AS/HFA had a mean AQ score of 35.8 (SD = 6.5), significantly higher than Group 2 controls (M = 16.4, SD = 6.3). 80% of the adults with AS/HFA scored 32+, versus 2% of controls. Among the controls, men scored slightly but significantly higher than women. No women scored extremely highly (AQ score 34+) whereas 4% of men did so. Twice as many men (40%) as women (21%) scored at intermediate levels (AQ score 20+). Among the AS/HFA group, male and female scores did not differ significantly. The students in Cambridge University did not differ from the randomly selected control group, but scientists (including mathematicians) scored significantly higher than both humanities and social sciences students, confirming an earlier study that autistic conditions are associated with scientific skills. Within the sciences, mathematicians scored highest. This was replicated in Group 4, the Mathematics Olympiad winners scoring significantly higher than the male Cambridge humanities students. 6% of the student sample scored 32+ on the AQ. On interview, 11 out of 11 of these met three or more DSM-IV criteria for AS/HFA, and all were studying sciences/mathematics, and 7 of the 11 met threshold on these criteria. Test-retest and interrater reliability of the AQ was good. The AQ is thus a valuable instrument for rapidly quantifying where any given individual is situated on the continuum from autism to normality. Its potential for screening for autism spectrum conditions in adults of normal intelligence remains to be fully explored.

/pdf/the-autism-spectrum-quotient-aq-evidence-from-asperger-jpq494cv6w.pdf

The autism-spectrum quotient (AQ): evidence from Asperger syndrome/high-functioning autism, males and females, scientists and mathematicians.

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(07)61238-0.pdf

No health without mental health.

Two previous epidemiological studies of autistic twins suggested that autism was predominantly genetically determined, although the findings with regard to a broader phenotype of cognitive, and possibly social, abnormalities were contradictory. Obstetric and perinatal hazards were also invoked as environmentally determined aetiological factors. The first British twin sample has been re-examined and a second total population sample of autistic twins recruited. In the combined sample 60% of monozygotic (MZ) pairs were concordant for autism versus no dizygotic (DZ) pairs; 92% of MZ pairs were concordant for a broader spectrum of related cognitive or social abnormalities versus 10% of DZ pairs. The findings indicate that autism is under a high degree of genetic control and suggest the involvement of multiple genetic loci. Obstetric hazards usually appear to be consequences of genetically influenced abnormal development, rather than independent aetiological factors. Few new cases had possible medical aetiologies, refuting claims that recognized disorders are common aetiological influences.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033291700028099

Autism as a strongly genetic disorder: evidence from a British twin study.

The development of a new standardized investigator-based interview for use in the differential diagnosis of pervasive developmental disorders is described, together with a diagnostic algorithm (using ICD-10 criteria) based on its use. Good interrater reliability for algorithm items was shown between four raters, two in Canada and two in the UK, who rated 32 videotaped interviews. The items also significantly discriminated between 16 autistic and 16 nonautistic mentally handicapped subjects. The algorithm based on ICD-10 identified all 16 autistic individuals and none of the 16 nonautistic subjects.

Autism diagnostic interview: a standardized investigator-based instrument

Results from ROC curves of items from two scales, the Autism Diagnostic Interview (ADI) and Autism Diagnostic Interview-Revised (ADI-R), operationalizing DSM-IV criteria for autism are presented for 319 autistic and 113 other subjects from 8 international autism centers. Analyses indicate that multiple items were necessary to attain adequate sensitivity and specificity if samples with varying levels of language were considered separately. Although considering only current behavior was generally sufficient when a combination cutoff and additive model was employed, predictive power was highest when history was taken into account. A single set of criteria, as operationalized by individually structured questions in the ADI/ADI-R, was effective in differentiating autism from mental handicap and language impairment in subjects with a range of chronological ages and developmental levels.

Diagnosing Autism: Analyses of Data from the Autism Diagnostic Interview

Though a sex difference in the incidence of autism has frequently been reported, few studies have considered sex differences in the severity of features associated with autism. The Autism Diagnostic Interview was used to assess the difference between a group of 21 females and 21 males with autism with equivalent chronological nonverbal IQ greater than 60. Males were rated to be more severely autistic than females on several measures of early social development, but not in any other areas. Results are discussed in relationship to hypotheses based on sex differences in other populations.

Sex differences in higher functioning people with autism.

Objective. To assess the relationship between maternal depression and 4 parent-based prevention practices (use of car seats and electrical plug covers, presence of syrup of ipecac in the home, and reading to their child), using a large nationally representative follow-back sample. Methods. The maternal self-report components of 2 databases were used for this study, the 1988 National Maternal and Infant Health Survey and the linked companion 1991 Longitudinal Follow-Up Survey. A total of 7537 mothers with newborns in 1988 served as the subjects. Measures of the 4 prevention practices were extracted from the 1991 survey. Depressive symptom measures were derived from both surveys using the Center for Epidemiologic Studies-Depression Scale. Weighted bivariate and multivariate logistic analyses were used to assess the relationship between maternal depressive symptoms (trichotomized to depression at both time points, at 1 time point, and at neither time point) and parental prevention practices, while controlling for a wide variety of sociodemographic variables. Results. Mothers reporting a high level of depressive symptoms (Center for Epidemiologic Studies-Depression Scale score ≥16) reported significantly poorer prevention practices for car seat use, covering electrical plugs, and having syrup of ipecac in the home. High depressive symptoms were also related to a lower likelihood of daily reading, but only for those mothers presently living with a male partner. Engagement in all prevention practices, except having syrup of ipecac in the home, were less likely if the mother reported high levels of depressive symptoms at both time points versus a single time point. Conclusion. Maternal depression may significantly impede parental prevention practices. As maternal depression is a treatable condition, screening and treating this disorder may contribute to improvement in childhood prevention practices and ultimately child health.

Parental prevention practices for young children in the context of maternal depression.

Objective To examine the prevalence, persistence, and correlates of depressive symptoms in mothers of toddlers in a nationally representative sample. Method The self-report components of two linked databases were used for this study, the 1988 National Maternal and Infant Health Survey and the 1991 Longitudinal Followup. Depressive symptoms of 7,537 mothers were measured by the Center for Epidemiologic Studies-Depression Scale (CES-D) at both time points. Weighted bivariate and multivariate analyses were used to assess the stability of maternal depressive symptoms across two time points and maternal and child predictors of elevated depressive symptoms. Results Twenty-four percent of mothers at time 1 (mean child age 17 months) and 17% at time 2 (mean child age 35 months) had elevated depressive symptoms (CES-D score ≥16). Thirty-six percent of those with elevated scores at time 1 also had elevated scores at time 2. Not having breast-fed, a mistimed or unwanted pregnancy, and poor child health status were related to elevated depressive symptoms but not persistence. Conclusions Elevated depressive symptoms are common in mothers of toddlers. Given the potential magnitude of need, a systematic clinical and public health approach may be required.

John D. McLennan

Papers

Autism diagnostic interview: a standardized investigator-based instrument

Diagnosing Autism: Analyses of Data from the Autism Diagnostic Interview

Sex differences in higher functioning people with autism.

Parental prevention practices for young children in the context of maternal depression.

Prevalence, Persistence, and Correlates of Depressive Symptoms in a National Sample of Mothers of Toddlers