Depression has become a common mental illness, and It is crucial to establish and study depressive symptoms through early adolescence across adolescence to early adulthood. It is vital to characterize specific causes and certain types of depression in populations to help identify critical points for intervention and treatment. Studies on Depressogenic thinking (i.e., negative cognitive styles) in early adolescence suggest there is an association with the development of depressive mood in this age group. However, the long-lasting effect of depressogenic thinking is not known, especially in early adulthood or later ages. This project will examine how different profiles of depressogenic thinking are associated with varying types of depression and depressive mood (e.g., irritability, anhedonia, depressive thoughts, fatigue or sleeping) and identify the mechanisms underlying negative thoughts (styles) and later depression. Although CBT and medication are used in treatment for diagnosed cases of depression, this study may potentially develop early intervention strategies that may target early adolescence to improve depressogenic thinking to prevent depression in early adulthood and beyond.