Drug and alcohol abuse by people with severe and persistent mental illness (SPMI) is one of the most signifi cant problems facing the public mental health system. Referred to variously as people with dual disorders or dual diagnosis, mentally ill chemical abusers, and individuals with co-occurring psychiatric and substance disorders, these patients pose major problems for themselves, their families, clinicians, and the mental health system. Lifetime prevalence of substance abuse was assessed at 48% for schizophrenia and 56% for bipolar disorder in the Epidemiological Catchment Area study (Regier et al., 1990), and estimates of current abuse for the SPMI population range as high as 65% (Mueser, Bennett,.
