 The lifetime of substance use disorders in schizophrenia is close to 50. Substance abuse in schizophrenia is associated with negative consequences. Unfortunately, there no clear guidelines for the pharmacological treatment of this dual diagnosis population. Preliminary results suggest that second-generation antipsychotic drugs mainly clozapine may relieve drug cravings in schizophrenia. We performed a 12-week pilot study to evaluate the impact of quetiapine, a second-generation antipsychotic, on substance abuse parameters, psychiatric symptoms and side effects in patients schizophrenia and comorbid substance use disorders. Our expectation was a 20 decrease in drug cravings from baseline to end-point. 