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.

In 1997 in this Journal we published the ‘‘Reading the Mind in the Eyes’’ Test, as a measure of adult ‘‘mentalising’’. Whilst that test succeeded in discriminating a group of adults with Asperger syndrome (AS) or high-functioning autism (HFA) from controls, it suered from several psychometric problems. In this paper these limitations are rectified by revising the test. The Revised Eyes Test was administered to a group of adults with AS or HFA (N fl 15) and again discriminated these from a large number of normal controls (N fl 239) drawn from dierent samples. In both the clinical and control groups the Eyes Test was inversely correlated with the Autism Spectrum Quotient (the AQ), a measure of autistic traits in adults of normal intelligence. The Revised Eyes Test has improved power to detect subtle individual dierences in social sensitivity.

https://depts.washington.edu/uwcssc/sites/default/files/hw00/d40/uwcssc/sites/default/files/Mind%20in%20the%20Eyes%20Scale_0.pdf

The ''Reading the Mind in the Eyes'' Test Revised Version: A Study with Normal Adults, and Adults with Asperger Syndrome or High-functioning Autism

Empathy is an essential part of normal social functioning, yet there are precious few instruments for measuring individual differences in this domain. In this article we review psychological theories of empathy and its measurement. Previous instruments that purport to measure this have not always focused purely on empathy. We report a new self-report questionnaire, the Empathy Quotient (EQ), for use with adults of normal intelligence. It contains 40 empathy items and 20 filler/control items. On each empathy item a person can score 2, 1, or 0, so the EQ has a maximum score of 80 and a minimum of zero. In Study 1 we employed the EQ with n = 90 adults (65 males, 25 females) with Asperger Syndrome (AS) or high-functioning autism (HFA), who are reported clinically to have difficulties in empathy. The adults with AS/HFA scored significantly lower on the EQ than n = 90 (65 males, 25 females) age-matched controls. Of the adults with AS/HFA, 81% scored equal to or fewer than 30 points out of 80, compared with only 12% of controls. In Study 2 we carried out a study of n = 197 adults from a general population, to test for previously reported sex differences (female superiority) in empathy. This confirmed that women scored significantly higher than men. The EQ reveals both a sex difference in empathy in the general population and an empathy deficit in AS/HFA.

The empathy quotient: an investigation of adults with Asperger syndrome or high functioning autism, and normal sex differences.

Objective Autism spectrum disorders are now recognized to occur in up to 1% of the population and to be a major public health concern because of their early onset, lifelong persistence, and high levels of associated impairment. Little is known about the associated psychiatric disorders that may contribute to impairment. We identify the rates and type of psychiatric comorbidity associated with ASDs and explore the associations with variables identified as risk factors for child psychiatric disorders. Method A subgroup of 112 ten- to 14-year old children from a population-derived cohort was assessed for other child psychiatric disorders (3 months' prevalence) through parent interview using the Child and Adolescent Psychiatric Assessment. DSM-IV diagnoses for childhood anxiety disorders, depressive disorders, oppositional defiant and conduct disorders, attention-deficit/hyperactivity disorder, tic disorders, trichotillomania, enuresis, and encopresis were identified. Results Seventy percent of participants had at least one comorbid disorder and 41% had two or more. The most common diagnoses were social anxiety disorder (29.2%, 95% confidence interval [Cl)] 13.2-45.1), attention-deficit/hyperactivity disorder (28.2%, 95% Cl 13.3-43.0), and oppositional defiant disorder (28.1 %, 95% Cl 13.9-42.2). Of those with attention-deficit/hyperactivity disorder, 84% received a second comorbid diagnosis. There were few associations between putative risk factors and psychiatric disorder. Conclusions Psychiatric disorders are common and frequently multiple in children with autism spectrum disorders. They may provide targets for intervention and should be routinely evaluated in the clinical assessment of this group. J. Am. Acad. Child Adolesc. Psychiatry , 2008;47(8):921-929.

Psychiatric disorders in children with autism spectrum disorders: Prevalence, comorbidity, and associated factors in a population-derived sample

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.

Background: The Virginia Twin Study of Adolescent Behavioral Development is a cohort-longitudinal epidemiological study that uses the genetic twin design to study the development and maintenance of child psychiatric disorders. We determined the rates of DSM-III-R disorders, disorders with impairment, and age, sex, and co-morbidity effects. Methods: Families of 2762 white twins aged 8 to 16 years participated. Twins and their parents were asked systematically about risk factors and current psychiatric symptoms by means of investigator-based psychiatric interviews and questionnaires. The DSM-III-R diagnoses were made for major depressive disorder, separation anxiety, overanxious disorder, simple phobia, social phobia, agoraphobia, oppositional defiant disorder, conduct disorder, and attention deficit hyperactivity disorder. Results: The 3-month point prevalence for any DSM-III-R disorders was 413 per 1000, and that for disorders with associated impairment was 142 per 1000. Emotionnal disorders with impairment occurred in 89 per 1000, with girls being more commonly affected; behavioral disorders had a prevalence of 71 per 1000, with boys being more frequently affected. The proportion with disorder who also had functional impairment varied across disorders; anxiety and phobic disorders were particularly likely not to be accompanied by impairment. Rates of emotional and behavioral disorders increased over the age range. There was extensive comorbidity among disorders. Conclusions: The prevalence rates and patterns of findings from this study of twins are consistent with those of other epidemiological studies, supporting previous findings of few differences in rates of psychiatric disorder between twins and singletons. The importance of including measures of functional impairment is evident by its effect on rates of disorder and patterns of comorbidity.

The Virginia Twin Study of Adolescent Behavioral Development: Influences of Age, Sex, and Impairment on Rates of Disorder

Background. Previous studies on assortment for psychiatric disorders have reported discrepant findings. We aimed to test whether there is a significant association for psychiatric diagnoses, including alcoholism, generalized anxiety disorder, major depressive disorder, panic disorder and phobias between husbands and wives in two population-based samples. We further evaluated whether marital resemblance occurs primarily within or across psychiatric disorders and if assortment for psychopathology is primary or secondary to assortment for correlated variables. Methods. A model for mate selection addressed whether the correlation between mates for psychiatric disorders arises from direct assortment (primary homogamy) or through correlation with other variables for which assortment occurs (secondary homogamy) or through cross-variable assortment. The model accounted for within-person co-morbidity as well as across-spouse data. Results. Findings suggested that a moderate degree of assortment exists both within and across psychiatric diagnoses. Only a small amount of the observed marital resemblance for mental illness could be explained by assortment for correlated variables such as age, religious attendance and education. Similar results were obtained for the two samples separately and confirmed in their joint analysis, revealing that the co-morbidity and assortment findings, except for the marital correlation for age, religious attendance and education, replicate across samples. Conclusions. Significant but moderate primary assortment exists for psychiatric disorders. The bias in twin studies that have ignored the small amount of assortment is negligible.

Assortative mating for major psychiatric diagnoses in two population-based samples

The Virginia Twin-Family Study of Adolescent Behavioral Development (VTSABD) is a current longitudinal study of psychopathology in 1412 pairs of 8-16-year-old Caucasian twins and their parents. The primary aim of the study is to evaluate family-genetic and environmental risk factors for major domains of psychopathology in families representative of the Virginia Caucasian population. In this report, we utilize census-derived indices of neighbourhood income and urban residence to identify departures from population representation arising at the time of family enrollment in the twin registry and family participation in a psychiatric interview. Furthermore, we consider whether demographic sample biases influenced prevalence rates of adult psychopathology (including major depression, generalized anxiety disorder, alcohol dependence, phobias, and panic disorder) in the VTSABD. Results indicated that families that enrolled in the twin registry (83% of those identified by Virginia schools) and that participated in the home interview (75% of those targeted) resided in urban and rural communities with a range of per capita income levels representative of the Virginia population. However, participation biases operated throughout the study and were primarily characterized by losses of families living in low income, urban communities. There was also a smaller number of families living in high income neighbourhoods that did not enroll in the twin registry or that indefinitely postponed the psychiatric interview. These biases had small effects on prevalence rates of adult psychopathology in the VTSABD sample, even though neighbourhood income was significantly related to a subset of adult diagnoses. We emphasize the usefulness of the census methodology in evaluating sample biases in population-based psychiatric genetic studies.

Emily Simonoff

Papers

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

The Virginia Twin Study of Adolescent Behavioral Development: Influences of Age, Sex, and Impairment on Rates of Disorder

Assortative mating for major psychiatric diagnoses in two population-based samples

The Virginia Twin-Family Study of Adolescent Behavioral Development: assessing sample biases in demographic correlates of psychopathology.

Retrospective recall recalled.