[Obsessive-compulsive disorder and schizophrenia. A critical review].

Co-occurrence of psychotic and obsessive-compulsive symptoms has been recognized for decades. This paper reviews published reports from five perspectives: schizophrenia with obsessive-compulsive symptoms, obsessive-compulsive disorder (OCD) with psychotic symptoms, schizophrenia-spectrum-personality disorder with obsessive-compulsive symptoms, obsessive-compulsive symptoms induced by atypical antipsychotics and similarities of functional neural circuits theory in OCD and schizophrenia. A MEDLINE search was conducted to identify relevant articles from 1960 until 2004. Only a few systematic data that explore the nature and significance of such occurrence have been published. More recent studies using systematic diagnostic criteria suggest that the rate of occurrence may not be rare at all. In schizophrenia, a similar dorsolateral prefrontal cortex circuit shares anatomic substrates similar to those of the OCD orbitofrontal circuit. Exploring the interface of schizophrenic and obsessive-compulsive symptoms is important for diagnostic clarity and could have important implications for treatment and long-term prognosis. The review emphasizes the different origins and natural course of co-occurrence of schizophrenic and obsessive-compulsive symptoms and their various outcome under atypical antipsychotics and selective serotonin reuptake inhibitors (SSRI). Further double-blind, randomized, placebo-controlled investigations in larger cohorts of schizophrenic and OCD patients are needed in order to identify a schizo-obsessive schizophrenia and a schizotypal subtype of obsessive compulsive disorder and to substantiate the algorithm for treatment.