Objective: To examine whether subjective well-being and craving for cannabis were different in patients with schizophrenia or related disorders treated with either olanzapine or risperidone.
Method: A 6-week, double-blind, randomized trial of olanzapine and risperidone was carried out in 128 young adults with recent onset schizophrenia or related disorders. Primary efficacy measures were the mean baseline-to-endpoint change in total scores on the Subjective Well-Being under Neuroleptics scale, the Obsessive-Compulsive Drug Use Scale, the Drug Desire Questionnaire, and the cannabis use self-report. An analysis of covariance was used to test between-group differences.
Results: Estimated D(2) receptor occupancy did not differ between olanzapine (n = 63) and risperidone (n = 65). Similar improvements in subjective well-being were found in both groups. In the comorbid cannabis-using group (n = 41, 32%), a similar decrease in craving for cannabis was found in both treatment conditions.
Conclusions: Both olanzapine and risperidone were associated with improved subjective well-being. No evidence was found for a differential effect of olanzapine or risperidone on subjective experience or on craving for cannabis in dosages leading to comparable dopamine D(2) occupancy.
Clinical trial registration number: ISRCTN46365995.