Pharmacotherapy for schizophrenia and co-occurring substance use disorders

Research on the optimal pharmacotherapy for people with schizophrenia and co-occurring substance use disorders remains in its infancy. This report reviews existing data and provides an update on recent research. The confluence of findings is consistent with a model of a reward dysfunction inherent in the neuropathology of schizophrenia, leading to a heightened vulnerability of people with schizophrenia to substance use disorders. Studies indicate that patients with dual disorders have difficulty tolerating conventional antipsychotics, have higher rates of medication nonadherence, and have greater impulsivity and sensation seeking. Limited evidence suggests that clozapine treatment may be associated with reduced substance abuse, with weaker evidence suggesting that other novel antipsychotics may have similar, but potentially less potent, effects. Controlled trials to test the effects of these medications are underway. A number of recent studies indicate that bupropion can facilitate reduced tobacco smoking among patients with schizophrenia. The preferential use of novel antipsychotics, a lower threshold for prescription of clozapine, the use of bupropion for smoking cessation, careful monitoring of compliance, and possible use of other medications for substance use disorders when indicated are recommended in pharmacologic management for people with co-occurring substance use disorders and schizophrenia.