The associations between rumination and depression in late adolescence: a longitudinal study using the IMAGEN adolescent cohort

BackgroundDepression is a leading cause of global disease burden, yet effective prevention strategies remain limited. Identifying targetable risk factors is therefore a priority. Rumination, a style of repetitive negative thinking, has been linked to depression and anxiety, but has traditionally been viewed a symptom of depressive episodes rather than a cognitive vulnerability. Moreover, previous studies have not consistently addressed key confounders such as anxiety or the possibility of reverse causality. This study aimed to examine the longitudinal and bidirectional associations between rumination and depression in adolescents.MethodsParticipants were drawn from the IMAGEN adolescent cohort. Depression was assessed using the Development and Wellbeing Assessment (DAWBA), and rumination using the Ruminative Responses Scale (RRS), at ages 18 and 22. Bidirectional longitudinal associations were examined using logistic and linear regression models. Analyses were conducted unadjusted and adjusted for a range of confounders, including baseline symptoms and anxiety.Results Complete data were available for 800 adolescents (59.66% female, 40.12% male, mean age at first time point 18.42 years, SD=0.67). Higher rumination at age 18 was associated with depression at age 22, including after adjustment for confounders (adjusted OR=1.45, 95% CI 1.14–1.86, P=0.003). In contrast, there was no evidence that depression at age 18 was associated with rumination at age 22 after adjustment (mean difference = -0.52, 95% CI -1.69–0.64, P=0.379).ConclusionOverall, these findings indicate that rumination is associated with later depression from late adolescence into early adulthood, independent of baseline symptoms and confounders, with no evidence of reverse effects. This supports rumination as a vulnerability marker and a potential target for prevention, although intervention studies are needed to test causal effects.