2022

Background. There are numerous observations of reward sensitivity being associated with different psychiatric disorders. Nonetheless, most studies investigating this relationship have been cross-sectional. Additionally, current knowledge is fragmentary as studies often investigate only one disorder at a time. The present study addresses these gaps by investigating whether reward sensitivity at age 13 predicts the course of nine psychopathology domains (attention and hyperactivity, autism spectrum, reactive aggression, proactive aggression, mood, anxiety, smoking, alcohol use, and cannabis use) over a 14-year follow-up period. Methods. We used dimensional outcomes on 2,523 individuals over five measurement waves between ages 13 and 26 of the Dutch Tracking Adolescents' Individual Lives Survey (TRAILS). Reward sensitivity was measured with the Behavioral Activation System (BAS) scale. The longitudinal associations between reward sensitivity and psychopathology were examined using growth curve analysis within a multilevel framework. Results. Reward sensitivity at age 13 was associated with changes in psychopathology over time. Reward sensitivity had a stable main effect on the future course of reactive and proactive aggression problems and anxiety problems. The effect of reward sensitivity increased over time for alcohol and cannabis use. Post-hoc analyses showed that reward sensitivity also had a stable effect on attention problems and hyperactivity and smoking when based on the fun-seeking subscale for both domains and when changing the informant who reported on attention problems and hyperactivity. No evidence was found for a longitudinal association between reward sensitivity and autism spectrum problems and mood problems. Conclusion. The current study provides evidence for the long-lasting effects of reward sensitivity on the course of different domains of psychopathology.

Objective. This study tested two opposing hypotheses on the continuity of psychopathology throughout adolescence and young adulthood; differentiation versus dynamic mutualism. Differentiation predicts that co-occurrence decreases, while dynamic mutualism predicts that co-occurrence increases due to causal interactions amongst mental health problems. Method. Using data from the Dutch TRacking Adolescents' Individual Lives Survey (n = 2228, 51% female), we studied the development of self-reported internalizing, externalizing, and attention problems at ages 11 to 26 across six waves. Random-intercept cross-lagged panel modeling was employed to distinguish within-person development from stable between-person processes. Results. Large stable between-person associations indicated that adolescents with internalizing problems tended to have both externalizing and attention problems as well. On a within-person level, mental health problems showed partial stability and strong cross-sectional co-occurrence. Within-wave associations of internalizing with externalizing or attention problems decreased between age 11 and 16 years, after which they increased again. Little heterotypic continuity was found: age 11 externalizing predicted age 13 attention, which in turn predicted age 16 externalizing problems, and internalizing predicted externalizing problems across ages 22 to 26. Findings were similar for males and females. Conclusions. Our findings suggest co-occurrence decreases during early and middle adolescence, supporting differentiation. While co-occurrence increased again into young adulthood, this could not be labeled as dynamic mutualism because little evidence for heterotypic continuity was found in this phase of life. The strong stable links between internalizing, externalizing, and attention problems stress the importance of targeting these mental health problems and their shared risk factors together.