The aim of the study is to investigate the validity, reliability and clinical features of a Danish version of the Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS-R). A self-reporting scale devise used as a supplementary questionnaire in diagnosing autism spectrum disorder (ASD) in adults. Furthermore the validity of novel screening questionnaire: SchiZotypal Autism Questionnaire (ZAQ), will be investigated. ZAQ is developed to discriminate Schizotypal Disorder from ASD.

The study has 2 parts.

Part 1:

The objective is to develop and validate a self-report screening questionnaire to efficiently discriminate between Schizotypal Disorder (SD) and Autism Spectrum Disorder (ASD) within the adult population. Discriminating ASD from SD in a clinical setting is a complex and time-consuming task, as they share considerable features both at the symptomatic and the diagnostic criteria. A pilot version of this questionnaire have been developed with 139 questions and named schiZotypy Autism Questionnaire (ZAQ), to discriminate between these conditions.

Part 2:

RAADS-R scale, which is a clinical tool that aims to better identify autism spectrum disorders The scale is a self-administered questionnaire completed by the patient himself assisted by a clinician (psychiatrist, psychologist) which ensures the understanding of issues and the choice of answers. The scale contains 80 items including 64 questions describe specific symptoms of autism spectrum disorders and 16 questions to describe non-symptomatic behaviors.

The objective of this study is to perform a complete validation of this scale in a Danish translation.

For both parts of the study 600 adults will be included, 200 adults referred for assessment of autism, 200 adults with another psychiatric disorder, and 200 adults without psychiatric disease.

Inclusion Criteria:

1. Al patient referred to the outpatient clinic for ADHD and Autism at PCG, in the research period, for diagnostic assessment of Autism Spectrum Disorder (Pervasive Developmental Disorder, infantile autism, atypical autism and Asperger Syndrome)

2. WAIS > 85, or Raven or no-clinical suspicion and education level of 11 years or above

3. Completion of

   1. Clinical assessment
   2. Adult Asperger Assessment (AAA)
   3. Psychopathology evaluation using DSM-V
   4. A conclusion based on interdisciplinary consensus

Exclusion Criteria:

1. Insufficient Danish language skills
2. Acute psychiatric illness prompting departure/dismissal from the diagnostic assessment