Abstract
BACKGROUND: There are a lack of a societal perspective and a comprehensive approach to adolescents’ wellbeing and their declining mental health. We study here changes in Finnish adolescents’ self-rated health (SRH) in 1981–2025, and how SRH associated with societal changes, and sociodemographic and school-related factors during these years. METHODS: Two data sets of 14-year-old Finns were used: nationwide postal/internet surveys 1981–2019 (N = 28 960) and school-surveys 2000–2025 (N = 604 758), both conducted biennially. Explanatory variables for low SRH in gender-stratified logistic regression analyses were survey year, sociodemographic factors (gender, parents’ education and smoking, family structure), and school-related factors (teacher relationship, classroom atmosphere, learning difficulties, school performance). RESULTS: The prevalence of low SRH remained steady in 1981–2015. From 2015 onwards, low SRH started to increase, but only among girls, peaking in 2023. All explanatory variables were associated with SRH, but their changes accounted for 9% of the increase in girls’ low SRH. Minor variations were observed in the associations between SRH and the explaining variables over time, except a strengthened association between low SRH and learning difficulties in 2015–2023. CONCLUSION: Before 2015, adolescents’ low SRH remained relatively steady, despite improvements in family sociodemographic indicators, positive changes in school environment, and factors such as the economic recession in the 1990s. From 2015 onwards, the gender gap began to widen, peaking during COVID-19 pandemic, consistent with previous studies on gender differences in mental health. Concurrently, the strong association between low SRH and learning difficulties further strengthened among both genders, despite that known risk factors diminished in families and school environment improved. Further research is necessary to reveal factors that influence adolescents’ wellbeing and learning in contemporary society. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-026-27022-y.