Subtyping of substance use disorders in a high-risk welfare-to-work sample: a latent class analysis.

The goals of this study were (a) to investigate the existence of substance abuse/dependence subtypes in a diverse low-income welfare to work sample and (b) to explore subtype differences in rates of comorbid psychiatric and medical conditions. Data for all demographic and clinical variables were extracted from deidentified case records of 4,977 clients enrolled in a comprehensive case management program for welfare recipients with substance use disorders. Latent class analysis supported a five-class model made up of a multiple abuse/dependence class (n = 1,133), a cocaine/alcohol class (n = 2,120), an opioids class (n = 1,346), a cannabis class (n = 362), and a small polysubstance/none primary class (n = 16). Post hoc chi-square analyses revealed several between-class differences, perhaps reflecting differing levels of severity and service needs. All five classes were characterized by high rates of medical and psychiatric comorbidity.