This study presents the translation and validation of the Marijuana Expectancy Questionnaire (MEQ - Brazilian Adaptation), which evaluates the expectancy of results in marijuana use, important for treatment and prognosis related to addiction to this substance. The sample consisted of 400 subjects, 217 males and 183 females, of whom 147 were marijuana users and 253 were non-users. In the user group, 90 subjects were marijuana-dependent. Semantic validation of the MEQ-Brazilian Adaptation was confirmed after evaluation and suggestions by an expert review panel. In the Brazilian sample, 78 items were applied; however, the decision was made for a statistical analysis using the reduced scale (55 items), with similar psychometric properties. For both scales, an alpha = 0.89 was obtained. Discriminant validation of the reduced scale was statistically significant (p = 0.001). Temporal stability was examined using a 123-subject sample with a one-week interval between test and retest, indicating that the instrument obtains a consistent response pattern over time (r = 0.990). MEQ - Brazilian Adaptation presented good psychometric results and can be used in studies that aim to evaluate expectancy of results related to marijuana use.
Cannabis; Validation Studies; Questionnaires
