Temperament multi-trajectory groups across adolescence: Associations with adulthood psychopathology and polygenic...

It is well-established that adolescents' temperament trajectories predict future psychopathology. Less well understood is how temperament traits co-develop from adolescence to young adulthood. We characterized how youths' trajectories of effortful control, frustration, affiliation, and shyness formed multi-trajectory groups and examined their associations with adulthood psychopathology and polygenic risk scores (PRS). Participants were drawn from a larger longitudinal cohort (N = 1412). Effortful control, frustration, affiliation, and shyness were measured four times from ages 10-23. Adulthood internalizing and externalizing problems were measured at ages 24-27. PRS for externalizing problems and major depressive disorder were calculated. Group-based multi-trajectory analyses showed that a five-group model fit best, including "high-risk" on all temperament traits, "undercontrolled" and exuberant, "low-risk" on all traits, "overcontrolled" and inhibited, and "low affiliation" groups that differed on both the levels and slopes of temperament traits over time. The undercontrolled group showed the highest, and overcontrolled the lowest, externalizing PRS scores. The high-risk group showed heightened scores on the depression PRS. We found specific linkages between the high-risk group and withdrawn/depressed symptoms and the high-risk and undercontrolled groups with externalizing problems. Findings shed light on developmental patterns of temperament in adolescence-to-adulthood and unique combinations of temperament trajectories with specific linkages to etiologic factors and psychopathology.