Increasing student well‐being through a positive psychology intervention: changes in salivary cortisol, depression, psychological well‐being, and hope

Abstract The significant prevalence of mental health problems among children and adolescents is a major concern worldwide. The current study evaluates the impact of a year‐long, school‐based intervention, Flourishing Students, on adolescents' salivary cortisol levels, depressive symptoms, psychological well‐being, and hope. Utilizing a cluster randomized design with intervention and control classes, 72 students engaged in 32 well‐being lessons during academic year 2016–2017, whereas 68 students followed their standard curriculum. Depressive symptoms and psychological well‐being were assessed at three time points, while the stress hormone cortisol and hope were measured at two. The results showed a slight increase in cortisol levels from baseline to post‐intervention during school hours in the control group, whereas no change occurred in the intervention group. Additionally, total cortisol levels at post‐intervention were slightly lower among intervention‐group students compared with control group students. Questionnaire data revealed significant interaction effects on psychological well‐being and hope from baseline to post‐intervention, and on depression and psychological well‐being from baseline to the 5‐month follow‐up. The intervention group scored lower in depressive symptoms and higher in psychological well‐being and hope compared with the control group. These findings underscore the essential role of comprehensive assessment methods in evaluating intervention efficacy in well‐being programs.