This study examined the association and directionality of effect between mental wellbeing and depressive symptoms in Australian adolescents. Data were collected on two occasions 21 months apart. At Time 1, 1,762 10- to 14-year-old adolescents from a range of socio-economic status areas participated. At Time 2 (T2), 1,575 participated again. On both occasions, the Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS) and the Children's Depression Inventory 2 (CDI 2) were administered via online survey. Cross-lagged, longitudinal path analyses demonstrated a negative association between earlier symptoms of depression and later positive mental wellbeing, and that the reverse was also true, though weaker. The model accounted for 20% of the variance in males’ T2 CDI 2 depressive symptom scores (26% for females) and 21% of the variance in males’ T2 SWEMWBS mental wellbeing scores (23% for females). Depressive symptomatology and mental wellbeing were highly correlated, but symptoms of depression were more strongly associated with later mental wellbeing than vice versa. This has implications for educational psychologists, teachers, health professionals, and policy makers seeking to reduce depressive symptoms or promote mental wellbeing. Focusing solely on the promotion of mental wellbeing, without intervening to reduce symptoms of depression, may limit the potential outcomes that might be achieved.

This study examined associations between loneliness, a construct associated with serious adverse mental health outcomes, and positive mental wellbeing. Validated measures of loneliness (represented by friendship-related loneliness, isolation, positive attitude to solitude, and negative attitude to solitude) and positive mental wellbeing were administered to 1,143 adolescents from urban and rural schools. Confirmatory factor analyses revealed satisfactory model fit for both measures. A structural equation model confirmed significant positive associations between positive mental wellbeing and friendship-related loneliness and positive attitude to solitude; a significant negative association was found for isolation. Regression analyses provided support for significant differences in these associations according to gender, age, and geographical location (although only marginally). The implications of these findings during adolescence are reviewed.