Associations of Neuroticism, Impulsivity, and Aggression with Marijuana Use in the General U.S. Adolescent Population

Introduction: Marijuana use in adolescence is a major public health concern due to its high prevalence and negative health consequences. High neuroticism, impulsivity, and aggression have been suggested as correlates of illicit drug use, mostly in adults with chronic substance use problems. Less is known about associations of these personality traits with marijuana use in the general adolescent population. Positive changes in maladaptive personality traits are possible with early psychological interventions. Given recent changes in marijuana policy and the importance of early prevention, assessment of personality trait−marijuana use associations could inform intervention efforts. We hypothesized that neuroticism, impulsivity, and aggression would be positively associated with marijuana use in the general adolescent population.

Methods: We used data from the National Comorbidity Survey: Adolescent Supplement, a nationally representative, cross-sectional study of 10,148 U.S. adolescents aged 13 to 18 years. Age, gender, race, parent education level, poverty, and urbanicity were controlled in all analyses. Adjusted prevalence ratios (aPR) and odds ratios (aOR) were calculated to assess the associations between personality traits (neuroticism, impulsivity, and aggression) and marijuana use [lifetime use (yes: n=2,298 vs. no: n=7827), recent use in the past 12 months (yes: n=1,429 vs. no: n=862), early use (before the age of 14: n=924 vs. 14 or later: n=1,365), and frequency of use (heavy: n=388; moderate: n=421 vs. light: n=611)]. We examined gender as a potential moderator of the personality trait−marijuana use relationship.

Results: Neuroticism was significantly associated with higher lifetime use (aPR=1.04, 95% CI [CI]=1.02, 1.05) and recent use (aPR=1.01, CI=1.01, 1.02). Impulsivity showed significant positive associations with higher lifetime use (aPR=1.08, CI=1.07, 1.09), recent use (aPR=1.02, CI=1.01, 1.03), early use (aPR=1.01, CI=1.01, 1.03), and frequent use (heavy vs. light, aOR=1.09, CI=1.06, 1.13; moderate vs. light, aOR=1.05, CI=1.02, 1.09). Aggression showed significant positive associations with higher lifetime use (aPR=1.12, CI=1.11, 1.13), early use (aPR=1,04, CI=1.02, 1.06), and frequent use (heavy vs. light, aOR=1.09, CI=1.03, 1.14, moderate vs. light, aOR=1.09, CI=1.04, 1.14). The neuroticism−lifetime use association was stronger in females (aPR=1.05, CI=1.03, 1.07) than males (aPR=1.02, CI=1.01, 1.04). Female moderate users showed increased impulsivity than female light users (aOR=1.09, CI=1.03, 1.14), whereas no differences in impulsivity were found between male moderate users and male light users.

Conclusions: As hypothesized, all three personality traits showed associations with marijuana use. Impulsivityappears to be particularly linked with marijuana use, as it was correlated with all four marijuana use behaviors in our study. Increased neuroticism or impulsivity was associated with marijuana use for both genders, but especially for females. Present findings may help inform strategies for early identification and prevention approaches.