A two-year ethnography conducted among 16 dually diagnosed clients yielded two longitudinal findings. First, four “positive quality of life” factors were strongly correlated with clients' efforts to cease using addictive substances: (1) regular engagement in an enjoyable activity; (2) decent, stable housing; (3) a loving relationship with someone sober who accepts the person's mental illness; and (4) a positive, valued relationship with a mental health professional. Second, the study revealed that five “negative background factors” in participants' childhood homes were predictive of long-term continuation of substance use: (1) substance abuse in childhood home, (2) childhood household in dire poverty, (3) “non-functional” household members, (4) reporting of abuse imputed to care-givers, and (5) serious mental illness in household. The implications of these findings for treatment are discussed.