Objective: To determine the prevalence of obsessive-compulsive symptoms and obsessive-compulsive disorder in patients with schizophrenia or related disorders or subjects at ultra high risk for development of psychosis. Secondly, to determine the time of occurrence of obsessive-compulsive symptoms related to the onset of first psychosis.
Method: We collected data on all patients who were referred consecutively to our specialized clinic for first episode psychosis patients and ultra high risk subjects in Amsterdam between 1 July 2006 and 1 July 2008. Diagnosis of psychotic disorders was established using the Comprehensive Assessment of Symptoms and History schedule. Obsessions and compulsions were defined in accordance with DSM-III-R criteria and assessed by clinicians. We analyzed the onset of obsessive-compulsive symptoms and its relation to the onset of first episode psychosis.
Results: When a strict definition of obsessive-compulsive symptoms is used, 9.3% (n = 18) of patients with schizophrenia or a related disorder exhibited obsessive-compulsive symptoms and 1.5% also met criteria for obsessive-compulsive disorder. The onset of obsessive-compulsive symptoms occurred before, concurrent with and after onset of first episode psychosis in the following proportion of patients: 7/18, 3/18, 8/18. We found a prevalence of 20.7% of obsessive-compulsive symptoms in ultra high risk subjects.
Conclusion: Using a strict definition of obsessive-compulsive symptoms, we found relatively low prevalence rates of obsessive-compulsive symptoms and obsessive-compulsive disorder in patients with schizophrenia or related disorders; the rates are even lower than known rates of obsessive-compulsive symptoms and obsessive-compulsive disorder in the general population. Obsessive-compulsive symptoms rates in ultra high risk subjects are comparable to those in the general population. Further investigation of the predictive validity of obsessive-compulsive symptoms in ultra high risk subjects for developing psychosis is needed. Obsessive-compulsive symptoms either develop prior, during or after the onset of first episode psychosis.