Development and Validation of the Marijuana Motives Measure Short Form

Marijuana motives are a proximal variable to marijuana use. This research aimed to adapt and validate the short form of the Marijuana Motives Measure (MMM; Simons, Correia, Carey, y Borsari, 1998), the MMM SF, in Spanish. The sample comprised 232 participants (mean age = 25.11 (7.58), 50.43% males) who had tried marijuana at least once in their lifetime. Item and Rasch analyses were performed to choose the final pool of 15 items. Confirmatory Factor Analysis (CFA) showed an adequate 5-factor structure (S-BX2(80) = 121.30, p = .002; NNFI = .944; CFI = .958; IFI = .959; MFI = .915; RMSEA = .047(0.029, 0.063); AIC = -38.70), and the multi-group CFA between males and females showed acceptable fit indices (S-BX2(160) = 230.01, p = .000; NNFI = .900; CFI = .924; IFI = .927; MFI = .860; RMSEA = .062(.043, .078); AIC = -89.99). The questionnaire indicated metric (S-BX2diff (15) = 13.61, p = .556)), scalar (S-BX2diff (15) = 23.15, p = .081)) and error measurement invariance (S-BX2diff (15) = 8.65, p = .895)) between gender groups. The internal consistencies and ordinal omega of the scales were between .79 and .90. In the regression analysis, enhancement, coping and low conformity motives predicted frequency and quantity of marijuana smoked. The best predictor of frequency and quantity consumed during the heaviest smoking period was enhancement, while coping and, to a lesser extent, low conformity, were the only predictors of cannabis-related problems when marijuana frequency and quantity were controlled for. The MMM SF shows adequate psychometric properties and is a suitable instrument to assess marijuana motives, especially during time-limited sessions.Los motivos de consumo son una variable proximal al uso de marihuana. Este estudio pretende adaptar y validar la versión española breve del Marijuana Motives Measure (MMM; Simons, Correia, Carey, y Borsari, 1998), el MMM SF. La muestra estaba compuesta por 232 participantes (edad media = 25,11 (7,58), 50,43% hombres) que habían probado la marihuana al menos una vez. Se realizaron análisis de los ítems y de Rasch para seleccionar los 15 ítems. El Análisis Factorial Confirmatorio (AFC) mostró una estructura de cinco factores adecuada (S-BX2(80) = 121,30, p = ,002; NNFI = 0,944; CFI = 0,958; IFI = 0,959; MFI = 0,915; RMSEA = 0,047(0,029, 0,063); AIC = -38,70), y el AFC multigrupo entre hombres y mujeres mostró índices de ajuste aceptables (S-BX2(160) = 230,01, p = ,000; NNFI = 0,900; CFI = 0,924; IFI = 0,927; MFI = 0,860; RMSEA = 0,062(0,043, 0,078); AIC = -89,99). El cuestionario mostró invarianza métrica (S-BX2dif (15) = 13,61, p = ,556)), escalar (S-BX2dif (15) = 23,15, p = ,081)) y de los errores de medida (S-BX2dif (15) = 8,65, p = ,895)) entre grupos de género. Los alfas de Cronbach y omega ordinal de las escalas fueron de 0,79 a 0,90. Los motivos de animación, afrontamiento y bajos motivos de conformidad predijeron el consumo de marihuana. El mejor predictor durante la época de mayor consumo fueron los motivos de animación, mientras que los motivos de afrontamiento, y en menor medida los bajos motivos de conformidad, fueron los mejores predictores de los problemas derivados una vez se controló el efecto de frecuencia y cantidad fumada. El MMM SF presenta unas propiedades psicométricas adecuadas y es una medida útil para evaluar los motivos de consumo de marihuana, especialmente durante sesiones de evaluación con tiempo limitado