Lifestyle behavioural and socio-demographic predictors of distress and wellbeing among Australian adults

Lifestyle behaviours including physical activity (PA), dietary intake, and sleep are increasingly prominent targets in preventive mental health research and practice. Nevertheless, previous studies have typically adopted a model of mental health that discounts the potential for psychological distress and mental wellbeing to coexist. Reliance on linear regression modelling in extant research has also limited our understanding of how lifestyle behaviours interact with socio-demographic and other factors to predict distress and wellbeing. Among a sample of Australian adults (n = 1496) decision tree modelling was used to explore cross-sectional interactions between lifestyle behavioural and socio-demographic predictors of distress and wellbeing. In these models, sleep quality and frequency of moderate to vigorous PA-but not diet-predicted both distress and wellbeing outcomes. In contrast, higher self-reported health predicted wellbeing, but not distress. Overall, lifestyle behaviours interacted in complex ways with mental health variables and socio-demographic factors, with the predictors of distress often distinct from those of wellbeing. Our results align with a bivariate conceptualisation of mental health in which distress and wellbeing are overlapping but distinct continua. Preventive mental health research should adopt a bivariate conceptualisation to facilitate more precise and generative insights regarding the lifestyle behavioural correlates of mental health.