This application addresses the broad Challenge Area (05) Comparative Effectiveness Research (CER) and the specific Challenge Topic (05-MH-102) Cost Effectiveness of Mental Health Interventions. This study will conduct comparative cost-effectiveness analysis of 3 pairs of critical HIV mental health interventions: (1) abstinence-based interventions versus comprehensive sex education, (2) condom social marketing versus free condom distribution programs, and (3) HIV voluntary counseling and testing versus provider initiated testing and counseling. For each we will collect data from representative field intervention programs in developing countries on the cost per client to deliver each intervention. We shall cull results from systematic reviews and meta-analyses we have recently completed on the efficacy of each intervention. For provider initiated testing and counseling we shall conduct a systematic review and meta-analysis to allow for a full complement of comparative effectiveness analyses. Costing and cost-effectiveness analysis will be in accordance with methods recommended by the Panel on Cost-Effectiveness in Health and Medicine. Outcomes to be examined include the cost per: (a) quality adjusted life year (QALY) saved from each intervention, (b) disability adjusted life year (DALY) saved from each intervention, (c) HIV infection averted. We shall use a Bernoulli Process formula together with descriptive and behavioral data based on pooled effect size estimates from meta-analysis to model HIV incidence with and without the intervention. The US government has generously committed to a dramatic expansion of the AIDS prevention in recent years, with up to $39 billion now allocated for HIV prevention and care in developing countries. This is creating enormous demands on program managers and funding agencies to identify the best way to utilize these life- saving resources. Using meta-analytic analysis from systematic reviews on 6 interventions and cost data collected from field sites the study will identify crucial policy issues related to the comparative effectiveness of (1) abstinence-based interventions versus comprehensive sex education, (2) condom social marketing versus free condom distribution programs, and (3) HIV voluntary counseling and testing versus provider initiated testing and counseling.