Personal, social, and physical factors associations with depression in adolescence to adulthood

Abstract Background Numerous studies have tried to understand the causes of poor mental health, mostly focusing on single exposures. These approaches often fail to capture the complex and interconnected nature of poor mental health. This study aims to examine the associations of age-specific changes in explanatory factors, encompassing personal-, social-, health-, and lifestyle factors, and depressive symptoms in individuals aged 15 to 32 years. Methods Individuals born in 1989 were followed from 2004 to 2021, with surveys at ages 15, 18, 21, 28, and 32. Inverse probability weights and multiple imputations with chained equations were used to account for attrition and missing data. Descriptive characteristics for each wave were estimated, as well as changes in depressive symptoms and explanatory variables between each wave. Fixed-effect regression models and dominance analyses examined the contribution of change in each explanatory variables to the change in depressive symptom between each wave. Lastly, analyses of asymmetric change were conducted to detect asymmetric associations of explanatory variables and depressive symptoms. Results The relative importance of explanatory variables for depressive symptoms changed across waves. Stress symptoms were consistently the most dominant variable, with a relative contribution above 30% in all waves, while the contribution of sense of coherence increased from 17% to 25% across the waves. Self-esteem, self-rated health. and psychosomatic symptoms also showed high dominance, with shifting contributions over time. Although bullying did not have high dominance, it showed high associations with depressive symptoms during adolescence. Conclusions The associations between explanatory factors and depressive symptoms are dynamic over time. Preventive strategies for depressive symptoms should be tailored to the different factors at each life stage. Key messages • Stress symptoms, sense of coherence, self-esteem, self-rated health, and psychosomatic symptoms are relevant targets for preventing depressive symptoms. • The association between explanatory factors and depressive symptoms changes over time, therefore interventions should tailored to the different factors at each life stage.