Obsessive-Compulsive Symptoms in Patients With Schizophrenia: A Naturalistic Cross-Sectional Study Comparing Treatment With Clozapine, Olanzapine, Risperidone, and No Antipsychotics in 543 Patients

Objective: To compare the prevalence of obsessive-compulsive symptoms (OCS) in a population of patients with schizophrenia taking clozapine, olanzapine, or risperidone or taking no antipsychotic medication. Method: Baseline data of the Genetic Risk and Outcome of Psychosis study were collected between April 2005 and October 2008. We conducted a naturalistic cross-sectional study of 543 patients with schizophrenia and related disorders, who were recruited from multiple mental health centers, including inpatient and outpatient clinics, across The Netherlands. The patients met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria and were taking no antipsychotic medication or taking clozapine, olanzapine, or risperidone. OCS severity was measured with the Yale-Brown Obsessive Compulsive Scale. We compared patients to a sample of 575 healthy controls. Results: Prevalence of OCS in patients was significantly higher than in the control sample, 23.4% versus 4.9% (chi(2) = 73.8, P <.001). Patients taking clozapine reported OCS significantly more often during the last week (38.9%), when compared to patients taking olanzapine (20.1%, chi(2) = 10.02, P = .002) or risperidone (23.2%, chi(2) = 5.96, P = .015) and patients taking no antipsychotics (19.6%, chi(2) = 8.20, P = .004). Patients taking clozapine for 6 months or longer reported OCS significantly more often than patients taking clozapine for less than 6 months, 47.3% versus 11.8% (chi(2) = 6.89, P = .009). Conclusions: Treatment with clozapine in patients with schizophrenia is associated with a higher prevalence of OCS, especially when patients have been taking clozapine for 6 months or longer. We cannot rule out the possibility that this association is related to illness characteristics. Patients treated with risperidone or olanzapine or without treatment with antipsychotic medication had comparable prevalence of OCS, all significantly higher than the control sample. J Clin Psychiatry 2012;73 (11):1395-1402 (c) Copyright 2012 Physicians Postgraduate Press, In

Obsessive-compulsive symptoms in patients with schizophrenia: a naturalistic cross-sectional study comparing treatment with clozapine, olanzapine, risperidone, and no antipsychotics in 543 patients

To compare the prevalence of obsessive-compulsive symptoms (OCS) in a population of patients with schizophrenia taking clozapine, olanzapine, or risperidone or taking no antipsychotic medication.status: publishe

Differences in craving for cannabis between schizophrenia patients using risperidone, olanzapine or clozapine

Substance abuse and psychotic disorders have a high rate of comorbidity. Both disorders are associated with changes in the dopaminergic transmission in the mesocorticolimbic pathways of the brain. Since antipsychotic medications interact with the dopamine receptors in these pathways, these medications could affect craving for substances. In the current study, the effect of clozapine (n = 27, mean dosage 350 mg), risperidone (n = 54, mean dosage 3.46 mg) and olanzapine (n = 60, mean dosage 13.78 mg) on subjective craving for cannabis was compared in 123 patients with cannabis dependence and psychotic disorder. Patients treated with risperidone reported significantly more craving compared with patients treated with clozapine (Z = -3.19, p = .001) or olanzapine (Z = -2.24, p = .025). No significant differences in craving between clozapine and olanzapine were found. These results are in concordance with findings in the literature on this subject and could be explained by differences in three dopamine mediated mechanisms of these compounds: 1) occupancy rate of dopamine D(2) receptors, 2) dissociation rate of dopamine D(2) receptors, 3) D(1)/D(2) occupancy ratio. Risperidone and clozapine show a maximal difference in D(2) receptor occupancy rate, dissociation rate and D(1)/D(2) ratio. Olanzapine is intermediate between risperidone and clozapine in these characteristics