A case-controlled study of repetitive thoughts and behavior in adults with autistic disorder and obsessive-compulsive disorder

Am J Psychiatry. 1995 May;152(5):772-7. doi: 10.1176/ajp.152.5.772.


Objective: The purpose of this study was to investigate the types of repetitive thoughts and behavior demonstrated by adults with autistic disorder and compare them with those of age- and sex-matched adults with obsessive-compulsive disorder.

Method: Fifty consecutive patients admitted to the Yale Adult Pervasive Developmental Disorders (Autism) Clinic with a primary diagnosis of autistic disorder (DSM-III-R and DSM-IV) completed the symptom checklist of the Yale-Brown Obsessive Compulsive Scale. Types of current obsessions and compulsions were evaluated. The comparison group consisted of 50 age- and sex-matched adults with obsessive-compulsive disorder (without tics) (DSM-III-R and DSM-IV).

Results: Direct discriminant function analysis showed that the patients with autistic disorder could be distinguished from those with obsessive-compulsive disorder on the basis of the types of current repetitive thoughts and behavior that they demonstrated. Compared to the obsessive-compulsive group, the autistic patients were significantly less likely to experience thoughts with aggressive, contamination, sexual, religious, symmetry, and somatic content. Repetitive ordering; hoarding; telling or asking (trend); touching, tapping, or rubbing; and self-damaging or self-mutilating behavior occurred significantly more frequently in the autistic patients, whereas cleaning, checking, and counting behavior was less common in the autistic group than in the patients with obsessive-compulsive disorder. In addition, a specific subset of seven obsessive-compulsive variables from the Yale-Brown Obsessive Compulsive Scale symptom checklist was identified that reliably predicted membership in the autistic group.

Conclusions: These results suggest that the repetitive thoughts and behavior characteristics of autism differ significantly from the obsessive-compulsive symptoms displayed by patients with obsessive-compulsive disorder. Future studies are warranted to assess the treatment response and neurobiological underpinnings of repetitive thoughts and behavior in patients with autism and obsessive-compulsive disorder.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Autistic Disorder / diagnosis*
  • Autistic Disorder / psychology
  • Case-Control Studies
  • Diagnosis, Differential
  • Discriminant Analysis
  • Female
  • Hospitalization
  • Humans
  • Male
  • Middle Aged
  • Obsessive-Compulsive Disorder / diagnosis*
  • Obsessive-Compulsive Disorder / psychology
  • Personality Inventory* / statistics & numerical data
  • Self-Injurious Behavior / diagnosis
  • Self-Injurious Behavior / psychology
  • Stereotyped Behavior / classification
  • Terminology as Topic