LAUSR

OBJECTIVE The present study investigated the relationship between difficulty initiating sleep and depressed mood and whether it is mediated by repetitive negative thinking. A moderating role of perfectionism was also examined. METHODS We surveyed 393 adolescents aged 14 to 20 years (M = 17.32, SD = 1.90) via an online questionnaire that assessed difficulty initiating sleep, repetitive negative thinking, perfectionism, and depressed mood. RESULTS Results indicated that repetitive negative thinking fully mediated the relationship between difficulty initiating sleep and depressed mood. In addition, this relationship was moderated by perfectionism, specifically, the relationship between repetitive negative thinking and depressed mood was stronger among more perfectionistic adolescents. CONCLUSIONS These findings highlight that repetitive negative thinking is significantly associated with both difficulty initiating sleep and depressed mood, supporting the conceptualization of repetitive negative thinking as a transdiagnostic process. Further, individual differences in perfectionism may amplify the relationship between repetitive negative thinking and mood. The role of repetitive negative thinking and perfectionism in explaining the link between sleep onset problems and depressed mood has important clinical implications through providing possible treatment targets.