De la sensibilité différentielle à la diathèse-stress dans la prédiction de la consommation de substances à l’adolescence : interactions entre l’environnement familial et le tempérament au cours du développement

Person-environment interactions predicting substance use can be interpreted according to several developmental theoretical models. The diathesis-stress model suggests that certain individuals (e.g., impulsive individuals) would have higher substance use levels compared to their peers when they are exposed to negative environments. The differential susceptibility model suggests that these same individuals would also have lower substance use levels than their peers when exposed to positive environments. The main objective of this thesis is to examine the diathesis-stress and differential susceptibility models in the context of interactions between temperament and the familial environment when predicting adolescent substance use. It includes four articles, i.e., one systematic literature review, two empirical studies and one perspective paper. The first article presents a systematic literature review on the interaction between temperament and the familial environment in the prediction of adolescent substance use and externalizing behaviors. Results show that interactions between temperament and the familial environment measured in childhood support the differential susceptibility model while interactions between temperament and the familial environment measured in adolescence support the diathesis-stress model. Since the a posteriori analyses for the models were limited methodologically, the next two articles examined the patterns of interactions a priori. The second article examines the interaction between temperament (impulsivity and inhibitory control at 6 years) and parenting practices (maternal coercive parenting at 6 years and parental knowledge at 14 years) in the prediction of alcohol use frequency at 15 years. Results show that an interaction between impulsivity and coercive parenting supports the differential susceptibility model. Thus, results support the findings of the literature review. The third article examines the interactions between personality (impulsivity and sensation seeking at 15 years) and parental knowledge at 15 years in the prediction of binge drinking frequency and drug use frequency at 15 and 17 years. Results show that the interactions between impulsivity and parental knowledge support the differential susceptibility model whereas the interactions between sensation seeking and parental knowledge support the diathesis-stress model. Thus, the developmental shift observed in the literature is supported for impulsivity, but sensation seeking could be a characteristic capturing sensitivity to positive and negative environments later in development. The fourth article offers a perspective that goes beyond adolescent externalizing behavior and substance use and proposes how the differential susceptibility model could apply to borderline personality disorder. The article presents how several personal characteristics associated with borderline personality disorder (e.g., emotional reactivity, impulsivity) could be markers of a sensitivity to positive and negative environments. Following these four articles, the discussion addresses key points such as: a revision of the notion of vulnerability, the importance of targeted prevention and the importance of thorough analyses of interaction effects.

Keyphrases: temperament, personality, impulsivity, family, parenting, environment, alcohol, drugs, externalizing problems, moderation