Bidirectional Associations Between Adolescents' Weekly Variation and Selection of Behavior, Well-Being, and Social Support During a Brief ACT-Based Internet Intervention

Abstract Background We investigated the extent to which adolescent ( n = 314) well-being (i.e., life satisfaction, internalizing symptoms) and social support predict weekly variation of behavior, adaptive behavioral selection, and maladaptive behavioral selection during a five-week internet intervention based on acceptance and commitment therapy (ACT) and the extent to which variation and selection of behavior predict well-being and social support. Additionally, gender and readiness to change were examined as predictors of individual differences. Methods Research questions were investigated using random intercept cross-lagged panel modeling. Results Higher variation, adaptive behavioral selection, and maladaptive behavioral selection were consistently associated with adolescents’ higher life satisfaction and social support. Cross-lagged and bidirectional within-individual associations became apparent towards the end of the intervention. Gender-based differences were identified in well-being, social support, and variation and selection of behavior and well-being, social support, and variation and selection of behavior were predicted differently by different stages of readiness to change. Conclusions The findings contribute to process-based literature by enhancing our understanding of the underlying between- and within-individual mechanisms during an ACT intervention for adolescents. The results provide valuable new knowledge on the weekly associations between adolescent well-being, social support, and variation and selection of behavior.