Personality trait change during adolescence as a predictor of later substance use, depressive symptoms, and perceived maturity

Adolescence is considered a critical period for understanding how individuals develop their self-concepts and personality dispositions, with the assumption that these changes presage important life outcomes. However, this tenet has been infrequently tested; few studies have included rigorous, frequent assessment of personality traits during adolescence, particularly from multiple rater perspectives. The current study utilizes data from the Oregon Youth Substance Use Project (OYSUP; N = 951), which followed students throughout their school years into early adulthood. Student- and teacher-reports of the Big Five personality traits were assessed yearly from grades 7 to 10, as well as drug use, well-being, and maturity outcomes later in emerging adulthood. Using latent growth curve models and true intraindividual change score models, results indicated that youth exhibited relative stability but significant trait changes on multiple domains during adolescence. Moreover, individual differences in these changes predicted likelihood for drug use and depressive symptoms later, as well as the students’ perceptions of their status as being developed adults, even when accounting for initial trait levels. Findings differed somewhat between youth- and teacher-reports of personality, with both demonstrating value for predicting young adult outcomes, indicating multiple perspectives of personality development are important. Plain language summary Adolescence is considered a critical period for understanding how individuals develop their self-concepts and personality dispositions, with the assumption that these changes presage important life outcomes. However, few studies have included frequent assessment of personality traits during adolescence, particularly from multiple rater perspectives. The current study utilizes data from the Oregon Youth Substance Use Project (OYSUP; N = 951), which followed students throughout their school years into early adulthood. Student- and teacher-reports of the Big Five personality traits were assessed yearly from grades 7 to 10, as well as drug use, well-being, and maturity outcomes later in emerging adulthood. Results indicated that youth exhibited relative stability but significant trait changes on multiple domains during adolescence. Moreover, how individuals changed over time predicted likelihood for drug use and depressive symptoms later, as well as the students’ perceptions of their status as being developed adults, even when accoun