Clozapine and Obsessions in Patients With Recent-Onset Schizophrenia and Other Psychotic Disorders.

Background: The increase or emergence of obsessions was compared in young patients with recent-onset schizophrenia or other psychotic disorders taking clozapine and other antipsychotic drugs.

Method: We conducted a retrospective cohort study. Subjects were 121 consecutively admitted patients diagnosed with DSM-III-R schizophrenia, schizoaffective disorder, schizophreniform disorder, or psychotic disorder not otherwise specified. Obsessions were diagnosed according to DSM-IV criteria.

Results: More clozapine-treated subjects (20.6%) than subjects treated with other antipsychotic drugs (1.3%) experienced an emergence or increase of obsessions (p < .01).

Conclusion: Use of clozapine is associated with the emergence or increase of obsessions in early-phase schizophrenia.