Obsessive-Compulsive, Psychotic, and Autism Dimensions Overlap in Real World: A Case Report.

Background: Obsessions, compulsions, and stereotypes are common psychopathological manifestations of obsessive-compulsive, psychotic, and autism spectrum disorders (ASDs). These nosological entities may be present in comorbidity, with relevant clinical difficulties in the differential diagnosis process. Moreover, ASDs are a complex group of disorders, with a childhood onset, which also persist into adulthood and present heterogeneous symptom patterns that could be confused with psychotic disorders.

Methods and results: We report a case of a 21-year-old man characterized by sexual and doubt obsessions; disorganized, bizarre, and stereotyped behaviors and compulsions; and social withdrawal, inadequate social skills, visual dispersions, and hypersensitivity to light stimuli. Obsessive and compulsive features were initially included within the differential diagnosis of psychotic and obsessive-compulsive spectrum disorders. However, aforementioned psychopathological elements did not improve when multiple antipsychotic drugs (olanzapine, haloperidol, and lurasidone) were administered in the hypothesis of schizophrenia and even worsened with clozapine therapy at a dose of 100 mg/d. Obsessions and compulsions progressively reduced during the fluvoxamine 14-week treatment paradigm at a dose of 200 mg/d. Considering the persistent deficits in social communication and interactions as well as the restricted interests pattern, a differential diagnostic hypothesis of ASD was formulated, and it was then confirmed at the final evaluation at a third-level health care center.

Conclusions: We discuss similarities and differences in the psychopathology of obsessions, compulsions, and stereotypes in the previously mentioned disorders, to underline factors that can help in the differential diagnosis of similar cases, and consequently in the appropriateness of treatment choice.