Treating comorbid substance use disorders in schizophrenia

Aim: To review the literature on pharmacological and psychosocial treatment approaches for people with schizophrenia and comorbid substance use disorder(s) (SUD). Method: Selective literature review. Results: Despite the high prevalence of comorbid SUD among people with schizophrenia, there is a considerable paucity of rigorously conducted randomized controlled treatment trials. While there is some evidence for clozapine, and for the adjunctive use of agents such as naltrexone for comorbid alcohol dependence, the available literature largely comprises case studies, case series, open label studies and retrospective surveys. In terms of psychosocial approaches, there is reasonable consensus that integrated approaches are most appropriate. Regarding specific aspects of care, motivational interviewing, cognitive behavioural therapy and contingency management have an emerging supportive literature, as do family interventions. However, there is no 'one size fits all', and a flexible approach with the ability to apply specific components of care to particular individuals, is required. Group-based therapies and longer-term residential services have an important role for some patients, but further research is required to delineate more clearly which patients will benefit from these strategies. Conclusions: While there is growing (albeit limited) evidence that integrated and well articulated interventions that encompass pharmacological and psychosocial parameters can be beneficial for people with schizophrenia and comorbid SUD, there remains a considerable gap in the literature available to inform evidence-based practice.