Background: Mental health and wellbeing are dynamic constructs influenced by a range of individual and contextual factors. Health behaviours—including protective behaviours (e.g., physical activity) and risk behaviours (e.g., alcohol consumption)—are established contributors to psychological outcomes. However, it remains unclear how changes in behavioural profiles over time predict shifts in mental health and wellbeing. This study examines the longitudinal associations between protective and risk-based behaviours and trajectories of depressive symptoms and wellbeing in a large national sample of Australian men.
Methods: Data were drawn from Waves 1 to 3 of the Australian Longitudinal Study on Male Health (Ten to Men). Analyses included participants (N=4,609) who provided data at two or more waves. Protective behaviours included fruit and vegetable intake and physical activity. Risk behaviours included sedentary time, alcohol consumption, smoking, and illicit substance use. Primary outcomes were depressive symptoms (PHQ-9) and personal wellbeing (PWI). Linear models examined associations between behaviours and changes in mental health over time, adjusting for sociodemographic covariates.
Results: Within-person reductions in alcohol use (β = –0.80, ~0.17 SD) and increased physical activity (β = –0.59, ~0.13 SD) had the largest positive influence on depressive symptoms, while changes in sitting, vegetable intake, and substance use showed smaller effects. In contrast, behavioural effects on wellbeing, after controlling for reduced depressive symptoms, were minimal. The only within-person association with wellbeing was for increased physical activity (β = 0.81, ~0.07 SD).
Conclusion: Depressive symptoms in men appear modestly responsive to behavioural change, particularly reductions in alcohol use and increased physical activity. In contrast, wellbeing showed limited responsiveness. These findings underscore the behavioural sensitivity of depression and support the importance of scalable behavioural interventions to improve population-level mental health outcomes in men.