The role of substance use in families' attributions and affective reactions to their relative with severe mental illness.

This study compared relatives' attributions and affective reactions toward patients with severe mental illness (SMI) only (N = 32) and patients with dual SMI and a substance use disorder (N = 36). Family members of patients with dual disorders perceived their ill relatives to have greater control over the causes of their psychiatric symptoms and to be more responsible for their symptoms than did family members of patients with SMI only. Key relatives of dual-diagnosed patients also reported more negative affect toward the patient than did key relatives of patients with SMI only, but the two groups did not differ in their level of positive affect. Consistent with attribution theory, severity of patients' substance abuse was positively associated with relatives' attributions of controllability, which, in turn, were positively associated with judgments of responsibility. Furthermore, judgments of responsibility were positively related to negative affect and inversely related to positive affect.