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.

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

Autism Diagnostic Observation Schedule

We provide a systematic review of epidemiological surveys of autistic disorder and pervasive developmental disorders (PDDs) worldwide. A secondary aim was to consider the possible impact of geographic, cultural/ethnic, and socioeconomic factors on prevalence estimates and on clinical presentation of PDD. Based on the evidence reviewed, the median of prevalence estimates of autism spectrum disorders was 62/10 000. While existing estimates are variable, the evidence reviewed does not support differences in PDD prevalence by geographic region nor of a strong impact of ethnic/cultural or socioeconomic factors. However, power to detect such effects is seriously limited in existing data sets, particularly in low-income countries. While it is clear that prevalence estimates have increased over time and these vary in different neighboring and distant regions, these findings most likely represent broadening of the diagnostic concets, diagnostic switching from other developmental disabilities to PDD, service availability, and awareness of autistic spectrum disorders in both the lay and professional public. The lack of evidence from the majority of the world's population suggests a critical need for further research and capacity building in low- and middle-income countries. Autism Res 2012, 5: 160–179. © 2012 International Society for Autism Research, Wiley Periodicals, Inc.

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Global Prevalence of Autism and Other Pervasive Developmental Disorders

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(06)69041-7.pdf

Prevalence of disorders of the autism spectrum in a population cohort of children in South Thames: the Special Needs and Autism Project (SNAP).

The Pre-Linguistic Autism Diagnostic Observation Schedule (PL-ADOS) is a semistructured observation scale designed for use as a diagnostic tool for children less than 6 years old who are not yet using phrase speech and are suspected of having autism. The PL-ADOS takes approximately 30 minutes to administer and is appropriate for use with this population because of its emphasis on playful interactions and the use of toys designed for young children. Reliability studies indicated that both individual activity ratings and summary ratings could be reliably scored from videotaped assessments by naive raters. Additionally, PL-ADOS scores of nonverbal preschool-aged children referred for clinical diagnosis and classified on the basis of a diagnostic team's clinical judgment, clearly discriminated between autistic and nonautistic developmentally disabled children. The resulting diagnostic algorithm is theoretically linked to diagnostic constructs associated with ICD-10 and DSM-IV criteria for autism.

The Pre-Linguistic Autism Diagnostic Observation Schedule

Summary codings for loss of communication skills asreported in the ADI-R and the additional questions weredeveloped in order to maximize the reliability of classi-ﬁcation, particularly within a single interview, whileusing as much information from the parent report aspossible. Initially, children were identiﬁed as having aloss on the basis of scores on standard and additionaltoddler ADI-R items indicating loss of speciﬁc languageor prelanguage communication skills (modiﬁed to in-clude any loss that lasted a month), or general loss ofany aspect of development. Written notes on each pro-tocol for each year in which an ADI-R was collected werethen checked for additional information and discrep-ancies. The information about word loss from the ﬁrstADI-R, when the children were 2 years old, was con-sidered most accurate, unless other clear, contradictoryinformation emerged. In general, while ADI-R codings ofword loss (of spontaneous and meaningful words and ofless clearly meaningful words) were helpful in screeningchildren with potential losses, reading the notes fromthe speciﬁc toddler questions and other items on theADI-R resulted in a smaller group of children consis-tently described as having loss of words than the ori-ginal ADI-R questions, as discussed below. Finalconsensus and decisions for coding were based onreasonable consistency (see below) of descriptionswithin the interview for each year and reliability ofscoring across examiners.Four categories were generated to describe loss ofcommunication:1. Loss of words was deﬁned as parent report of a childhaving used at least three words spontaneously on adaily basis for at least a month, followed by a periodof at least a month in which the child used norecognizable words. Words were deﬁned as consis-tent word-like sound–meaning correspondences,excluding ‘mama’ and ‘dada’, that were used spon-taneously and to which the parents were able toattribute a speciﬁc meaning. Thus, a child whoconsistently said ‘woof-woof’ to refer to a dog or said‘yum’ when she saw ice cream would be credited withhaving a word, but a child who whined in a particu-lar way when frustrated would not.2. Fluctuating word loss was a category applied tochildren who used at least three words on a dailybasis over a period of a month (though not neces-sarily the same three words in the same day) andused each word for at least a week, followed by atleast two periods of no words that lasted at least amonth. Words were deﬁned as above and had to beused spontaneously. This category was createdwhen it became evident that some children hadpatterns of repeated word losses but did not meet therequirements for the word loss category.3. Loss of vocalization was a heterogeneous categoryand included loss of fewer than three words, bab-bling, cooing, imitated vocalizations only, or othervocalizations not falling in the previous categories. Italso included children whose parents describedthem as having speech-like sounds, without clearmeaning, and then losing them. To be considered aspresent and lost, a behavior had to occur for at leasta month and be followed by at least a month withoutits occurrence.4. No word loss. This category was used for all otherchildren. It is important to note that some children inthis group were described as losing skills other thanvocal communication.

Pamela C. DiLavore

Papers

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

The Pre-Linguistic Autism Diagnostic Observation Schedule

Regression and word loss in autistic spectrum disorders

Autism Diagnostic Observation Schedule--Generic