Ziprasidone versus clozapine in the treatment of dually diagnosed (DD) patients with schizophrenia and cannabis use disorders: A randomized study

Background and Objectives Clozapine is considered to be particularly effective in the treatment of dually diagnosed (DD) patients with psychosis and substance use disorders. However, its use is restricted by potentially severe side effects. The aim of the present pilot study was to compare the effects of clozapine with the newer second generation antipsychotic (SGA) ziprasidone in DD‐patients. Methods Thirty (n = 30) patients with schizophrenia and cannabis abuse/dependence were randomized to ziprasidone or clozapine and were followed up for up to 12 months. Results Cannabis use was reduced in both groups during follow‐up. Clozapine treatment was associated with less positive symptoms of schizophrenia, more side effects and poorer compliance with treatment. Conclusions Results from this small pilot RCT suggest beneficial effects of both clozapine and ziprasidone in the treatment of cannabis use disorders in psychotic patients. Larger‐scale RCTs are needed in order to assess advantages and disadvantages of the different SGAs in dually diagnosed populations. (Am J Addict 2014;23:308–312)