Obsessive-compulsive symptoms frequent in schizophrenia but do not affect outcome

Clinically significant obsessive-compulsive (OC) symptoms appear to be common among patients with schizophrenia, but US study findings have shown that they do not impact on schizophrenia outcome.

Using an extensive, systematic, face-to-face screening of OC symptoms in 100 patients with schizophrenia or schizoaffective disorder, Matthew Byerly and colleagues, from the University of Texas Southwestern Medical Center in Dallas found that nearly one-third of patients exhibited such symptoms.

In total, 30% of patients had two or more OC symptoms, as measured on the Florida Obsessive Compulsive Inventory. Subsequent assessment of these 30 patients with the Yale Brown Obsessive-Compulsive Scale (YBOCS) indicated that 19 exhibited at least moderate OC symptoms, with a YBOCS score above 16, while five had severe OC symptoms, scoring 25 or more. Overall, 23 patients met full DSM-IV criteria for OC disorder. For the majority of patients, the OC symptoms were enduring, lasting for an average of 21.2 years.

Investigating the effect of OC symptoms on schizophrenia outcome in 58 of the original 100 patients, of whom 21 had OC symptoms while 37 did not, the researchers found no statistically significant difference between the two groups with regard to schizophrenia severity, as measured on the Positive and Negative Syndrome Scale, functional status, or rates of psychiatric hospitalization in the past 2 years.

They note that, in the majority (72%) of cases, OC symptoms occurred concurrently with or after the onset of schizophrenia, with an average time of just 6 months between the onset of the two conditions.

"Thus, factors directly or indirectly related to the psychotic disorder may be important contributors to the development of OC symptoms in persons with schizophrenia and schizoaffective disorder," Byerly and team write in the journal Schizophrenia Research.

They conclude: "Prospective long-term studies are needed to more fully characterize the occurrence and impact of OC symptoms in persons with schizophrenia and schizoaffective disorder."


Schizophr Res 2005; 76: 309-316