This study follows a representative sample of welfare recipients over 4 years, to examine changes in the longitudinal relationships between alcohol and drug problems and service use, poverty and unemployment in the welfare reform era. A representative sample of welfare recipients throughout an entire California county are surveyed in the Spring of 2001, as they apply for federal Temporary Aid to Needy Families (TANF, formerly Aid to Families with Dependent Children) and locally-funded General Assistance (GA). A representative sub-sample of these recipients - including an over-sample of problem drinkers and heavy drug users - are then followed and re-interviewed at 12, 24, 36 and 48 months after baseline. The objective is to test important new hypotheses raised by welfare reform concerning how key program changes are affecting clients with alcohol and drug problems, and changing their prospects for economic mobility and addiction recovery. The project uses event history analysis to study the relationships between alcohol and drug problems and cycles of welfare dependency. It examines alcohol's role in the circumstances surrounding particular welfare exit and re-entry events, including how these events can serve as predictors of subsequent welfare returns. Further analyses seek to better understand the associations between drinking, drug use and poverty conditions as they vary together over time and in relation to welfare dependency. Finally, the project examines today's enhanced welfare interventions for alcohol and drug treatment as factors that can alter the drinking trajectories and service careers of people on aid.