Dual diagnosis of substance abuse in schizophrenia: prevalence and impact on outcomes

Comorbid substance abuse disorders have emerged as one of the greatest obst acles to the effective treatment of persons with schizophrenia. Estimates o f the prevalence of such comorbidity vary, but as many as half of persons w ith schizophrenia may suffer from a comorbid drug or alcohol disorder. Youn ger age, male gender, and lower educational attainment are associated with greater risk for addiction. Persons with schizophrenia and comorbid addicti on tend to have an earlier onset of schizophrenia than do those without com orbid addiction. Research does not support a link between specific symptoms of schizophrenia and choice of abused drugs. Rather, drug choice is correl ated with the pattern of ambient drug use in the community. Comorbid substa nce disorders are associated with a variety of poorer outcomes, including i ncreased psychotic symptoms, poorer treatment compliance, violence, housing instability and homelessness, medical problems (including human immunodefi ciency virus infection), poor money management, and greater use of crisis-o riented services that result in higher costs of care. Considerable progress has been made over the past decade in understanding the need to integrate substance abuse treatment and mental health treatment to provide more effec tive care for this population. (C) 1999 Elsevier Science B.V. All rights re served.