People with Certain Personality Traits are Less Likely to Mature Out of Hazardous Substance Use, Study Suggests

The typical rise and fall of alcohol and cannabis consumption from late adolescence into adulthood does not hold for people with certain personality traits, a new study suggests. Among individuals who used both alcohol and cannabis, those with high impulsivity as adolescents showed a different developmental trajectory from their peers, according to a study in Alcoholism: Clinical & Experimental Research — the first to assess co-use of the two substances well into adulthood. Alcohol and cannabis are the two most frequently used psychotropic drugs in the US. High use is associated with negative health outcomes, particularly when the two substances are used concurrently or simultaneously. Little is known about the developmental course of alcohol and cannabis co-use into adulthood and whether it is influenced by sensation seeking and reduced conscientiousness, markers of disinhibition associated with hazardous substance use. Researchers at Arizona State University explored whether those personality traits could predict ongoing use through adulthood.

They worked with data from 458 participants drawn from a multi-generational study of familial alcohol use disorder (AUD), assessing co-use from late adolescence (18–22) through young adulthood (23–28) into adulthood (29–36). Participants reported on their typical alcohol and cannabis use, and negative consequences (e.g., “getting arrested,” “complaints from friends”). They also answered questions measuring sensation seeking in late adolescence (e.g., “I like wild parties”) and conscientiousness and neuroticism (e.g.,“I am pretty good about pacing myself” and “I often feel helpless and want someone to solve my problems”). Researchers found three groups based on participants’ substance use trajectories. They used statistical analysis to look for associations between patterns of alcohol and cannabis use, personality traits, family history of AUD, and demographic characteristics.

The first trajectory class — low-risk maturing out of alcohol use only — included 358 participants. As adolescents and young adults, they experienced low alcohol use, few negative consequences, and little or no cannabis use; their substance use declined into adulthood. The second class — high-risk maturing out of co-use — included 50 participants. They reported above average drinking and negative consequences, and very frequent cannabis use. This was arguably the riskiest consumption profile during late adolescence. Into adulthood, they drank less frequency, experienced fewer negative consequences, and their cannabis use declined. The third class — high-risk co-use switchers — included 50 participants who reported above average alcohol use and negative consequences. They had only miniscule changes in their drinking behavior into adulthood, accompanied by increasing cannabis use — perhaps the riskiest behavioral profile over time. Co-use of alcohol and cannabis was higher among men than women and among those reporting more sensation seeking in late adolescence. Lower conscientiousness during late adolescence was linked to being in the high-risk co-use switcher class. Neuroticism and family history of AUD were not associated with the trajectory class.

The researchers concluded that sensation seeking may predispose people to alcohol and cannabis use, while a lack of conscientiousness may impede maturing out of co-use. Health interventions targeting both alcohol and cannabis use in late adolescence and young adults could potentially make the difference between maturing out or continuing on a high-risk trajectory. Interventions based on personality traits and developmental stages could also be effective. Additional research is needed to test if findings are generalizable to other samples (e.g., 70% of participants were White).  

Maturing out of alcohol and cannabis co-use: A test of patterns and personality predictors. J. Waddell, J. Jager, L. Chassin. (pp xxx)

ACER-22-5300.R2