Alcohol use initiation is associated with changes in personality trait trajectories from early adolescence to young adulthood.

BACKGROUND Recent work has demonstrated the codevelopment of personality traits and alcohol use characteristics from early adolescence to young adulthood. Few studies, however, have tested whether alcohol use initiation impacts trajectories of personality over this time period. We examined the effect of alcohol use initiation on personality development from early adolescence to young adulthood. METHODS Participants were male (nmen = 2,350) and female (nwomen = 2,618) twins and adoptees from 3 community-based longitudinal studies conducted at the Minnesota Center for Twin and Family Research. Data on personality traits of Positive Emotionality (PEM; Well-being), Negative Emotionality (NEM; Stress Reaction, Alienation, and Aggression), and Constraint (CON; Control and Harm Avoidance)-assessed via the Multidimensional Personality Questionnaire (MPQ)-and age of first drink were collected for up to 4 waves spanning ages 10 to 32. RESULTS Alcohol use initiation was associated with significant decreases in levels of Well-being and CON traits, most notably Control; and significant increases in levels of all NEM traits, particularly Aggression. In general, the effects of alcohol use initiation on personality traits were moderated by gender and enhanced among those with earlier age of first drink. CONCLUSIONS From early adolescence to young adulthood, alcohol use initiation predicts deviations from normative patterns of personality maturation. Such findings offer a potential mechanism underlying the codevelopment of personality traits and alcohol use characteristics during this formative period of development.