Well‐being decline during adolescence: school transition as a predominant driver beyond age progression

BACKGROUND: The transition from primary-to-secondary school significantly impacts students' well-being. However, existing research provides limited insight into the long-term impact of school transition on well-being, and no studies have disentangled age-related changes from transition-specific effects. This study leverages a natural experiment, where an educational reform resulted in two different age cohorts transitioning simultaneously, to disentangle age effects from transition effects on student well-being. METHODS: This study analyzed longitudinal data from the Well-being and Engagement Collection census (2019-2025) in South Australia. Participants were two cohorts of students who simultaneously started secondary school in 2022: one transitioning at Year 7 and the other at Year 8. Well-being was measured across eight domains. Linear mixed-effects regression models examined transition effects and tested interactions with sociodemographic factors. RESULTS: A total of 20,910 participants (Male: 52.1%, Age in 2019: 9.7 ± 0.6) contributing 104,800 observations (5.0 responses/participant) across the 7 years were included. In the first 2 years post-transition, well-being experienced adverse changes across all domains (marginal effects for positively-worded measures: -0.44 to -0.18; negatively-worded measures: 0.08 to 0.13). The largest declines were observed in cognitive engagement (-0.44) and perseverance (-0.31). Younger and older cohorts experienced similar adverse changes; however, the younger cohort showed a larger well-being decline in the second-year post-transition. Females experienced more pronounced declines than males. The well-being decline among students residing in remote and very remote areas persisted until the third year after the transition. CONCLUSIONS: School transitions negatively affect students' well-being, with impacts that persist for more than 2 years. This decline was largely attributable to the school transition rather than age-related progression. Females and students residing in remote areas experienced greater declines in well-being than their counterparts. These findings highlight the need for transition-specific support strategies for vulnerable groups that extend beyond the first year of secondary schooling.