Longitudinal Association of Sluggish Cognitive Tempo with Depression in Adolescents and the Possible Role of Peer Victimization.

It is unknown whether sluggish cognitive tempo (SCT) is prospectively associated with depression in adolescence, and possible processes linking SCT to depression remain unexamined. Using a longitudinal study with three timepoints over a two-year period, the current study tested the indirect effects of SCT on depression via peer victimization, specifically physical, relational, and verbal victimization. Participants were 302 adolescents (M = 13.17 years; 44.7% female participants; 81.8% White; 52% with ADHD). In the fall of 8th grade, adolescents and parents completed measures of adolescents' SCT and ADHD symptoms. Adolescents completed a measure of peer victimization in spring of 8th grade and a measure of depressive symptoms in 10th grade. Models examining indirect effects were conducted with and without control of baseline ADHD and/or depressive symptoms. Across analyses, adolescent and parent ratings of SCT symptoms uniquely predicted greater depressive symptoms two years later when controlling for adolescent sex, study site, and either 8th grade depressive or ADHD symptoms. Further, adolescents' self-reported 8th grade SCT symptoms predicted 10th grade depressive symptoms via verbal victimization when controlling for 8th grade ADHD symptoms, but not in analyses incorporating 8th grade depressive symptoms. Findings underscore the predictive association of SCT on depressive symptoms, the possible role of adverse peer relationships as a mechanism linking SCT to depression, and the importance of considering ADHD and depressive symptoms in research on longitudinal correlates of SCT.