La consommation de cannabis et les comportements antisociaux de l’adolescent sont souvent associés et liés à des facteurs communs. Toutefois, le rôle de l’immaturité du jugement moral et des distorsions cognitives en lien avec la délinquance dans cette consommation n’a pas été étudié. L’objectif de cette étude était donc d’évaluer la contribution de ces variables. Neuf cent soixante-douze lycéens ont rempli des questionnaires mesurant la consommation de cannabis, la symptomatologie dépressive, l’anxiété sociale, l’estime de soi, les traits limites et psychopathiques, la maturité du jugement moral et les distorsions cognitives associées à la délinquance. Les variables socio-cognitives contribuaient significativement à expliquer la variance de la fréquence de la consommation de cannabis. Cette association pourrait suggérer une cible thérapeutique dans le traitement cognitivo-comportemental de la consommation de cannabis à l’adolescence.

Cannabis use and behavior delinquency tend to co-occur, to be associated and to share risk factors, more particularly among adolescents. However, the role of the immaturity of moral judgment and self-serving cognitive distortions in the explanation of cannabis use has not been studied. The aim of the present study was to evaluate the contribution of these factors to the prediction of cannabis use among adolescents girls and boys.

Participants were 972 high-school students (594 boys (61%); 378 girls (39%); mean age of boys=17.1±1.2; mean age of girls=16.7±1, P<0.001; age range=14–21). They completed self-report questionnaires measuring emotional variables (depressive symptoms, social anxiety and self-esteem), social cognitive variables (moral judgment and self-serving cognitive distortions), personality variables (borderline and psychopathic traits) and one item to evaluate the frequency of cannabis use.

Thirty-seven percent of boys (n=219) and 24% of girls (n=91) reported having used cannabis at least once during the last 6 months (P<0.001). Hierarchical multiple regression analyses were conducted to investigate the contribution of social cognitive variables to cannabis use among boys and girls. Social cognitive variables accounted for an increase of 4% in explained variance among boys and 3% among girls. The incremental F ratio exceeded critical F for the 0.5 level of significance, indicating that the social cognitive variables significantly increased the explained variance of the frequency of cannabis use in both genders.

The significant contribution of the social cognitive variables to the explanation of frequency of cannabis use does not indicate the causal direction of the relationship. It may be that immaturity of moral judgment or self-serving cognitive distortions may facilitate cannabis use. Conversely, cannabis use may modify social cognitive variables by enhancing cognitive impulsivity, by inducing social withdrawal which may contribute to alter moral judgment and cognitive empathy, through becoming used to transgressions, or through the influence of delinquent peers using cannabis. This link is probably bidirectional, cannabis use and disturbances of social cognitions influencing mutually negatively. A possible implication of these results might be to indicate a therapeutic target to cognitive interventions to reduce adolescent cannabis use.