Socioeconomic differences in adolescent health behaviors and their effect on inequalities in adult depressed mood: findings from a 27-year longitudinal study

BACKGROUND: Health behaviors have been posited to partly explain the association between socioeconomic status (SES) and health (i.e., the behavioral explanation of health inequalities), yet few studies have examined whether health behaviors serve as pathways from adolescent SES to adult depressive symptoms. This study aimed to explore the effects of adolescent health behaviors on adult depressed mood using the adolescent pathway model (APM). METHODS: Our sample consisted of n = 1109 Norwegians [45.5% female], who were surveyed from ages 13 to 40 across ten time points. Using linear regression analyses, we examined (1) the association between parental SES [household income and parental education] and adolescent health behaviors [breakfast regularity, leisure time physical activity (LTPA), difficulties falling asleep, alcohol consumption, and smoking], and (2) the associations between adolescent health behaviors and adult depressed mood, and whether these were moderated by indicators of parental SES. We also assessed how health behaviors are associated with social inequality in adult depressed mood. In this context, social inequality was defined as the covariance between adult SES (i.e., income and education) and adult depressed mood. RESULTS: Higher household income predicted higher levels of LTPA, and higher parental education predicted greater breakfast regularity. None of the health behaviors were associated with adult depressed mood, nor did they show moderation by SES. Adolescent health behaviors did not independently account for social inequality in adult depressed mood. CONCLUSIONS: The study suggests minimal socioeconomic differences in adolescent health behaviors, which do not significantly account for social inequalities in adult depressed mood. This offers limited support for the behavioral explanation of health inequalities within the framework of the APM. However, adolescent depressed mood emerges as the strongest predictor of adult depressed mood, highlighting its importance as a key focus for early intervention efforts.