Obsessive-compulsive symptoms in schizophrenia: implications for future psychiatric classifications.

Although obsessive-compulsive symptoms are not considered primary features, they are prevalent, independent of psychosis, and substantially modify clinical characteristics, course, treatment and prognosis of schizophrenia. The authors highlight the clinical significance of obsessive-compulsive symptoms in schizophrenia, provide diagnostic criteria for "schizo-obsessive" patients and address future directions for research.