The patient sample consisted of 698 cocaine-dependent patients [mean age 26.8±7.2 years; 96% males (n = 669)], recruited and evaluated as inpatients and outpatients from seven drug dependence treatment clinics in São Paulo, Brazil. All of the patients met the criteria for cocaine dependence established in the tenth revision of the International Classification of Diseases. At enrollment, each patient was subjected to a screening interview, designed specifically for use in Brazil, that included questions related to sociodemographic variables and to drug use [26].
