Effectiveness of Contingency Management in the Treatment of Crack Addiction for Individuals Living in the "Crackland" Region. A Single-blind Randomized Controlled Trial

The objective of this study is to evaluate the effectiveness of Contingency Management (CM) for crack users living in the "Crackland" region. To achieve this goal, regular treatment staff from Unidade Recomeço Helvétia treatment service will be capacitated in CM to latter-on apply the CM intervention in their respective services. The design will be a single-blind randomized clinical trial composed of a sample of 100 subjects with current diagnose for crack/cocaine dependence. Participants allocated to the control condition will receive 12 weeks of the usual care treatment provided by these two treatment facilities. Participants allocated to the experimental condition will receive the exact same treatment as control participants associated with CM. CM procedure will occur 2 timer per week (every Monday and Thursday or Tuesday and Friday). Primary outcomes are: (1)retention in treatment; (2) reduction of crack use; (3) promotion of continuous crack cocaine abstinence. Secondary findings are reduction on psychiatric symptomatology. The investigator hypothesis is that participants in the CM condition will have a better treatment response in all studied outcomes.