Positive psychology interventions may improve mental health, especially when tailored to individuals' needs and context. This randomized controlled study investigated the feasibility and effectiveness of just-in-time adaptive interventions (JITAIs) inspired by positive psychology principles. Students (N = 142) completed two experience sampling (ESM) periods of 15 days each. During the second period, participants who were randomly assigned to the intervention group (N = 72) received JITAIs. Mental health (i.e. well-being, anhedonia, depressive symptoms) was assessed before, after, and 3 months after the study. Although JITAIs were positively evaluated, they did not significantly impact momentary emotions or longer-term mental health. Qualitative analyses further showed that, while participants reported benefits from JITAIs, these interventions were not always considered necessary and introduced practical challenges. In conclusion, implementing JITAIs is feasible, but not consistently effective in improving mental health. Further research should investigate how to optimize just-in-time and adaptive delivery to better suit individual needs.
Positive psychology has linked character strengths to well-being but given less attention to whether broader philosophical frameworks enrich how strengths are understood and practised. This study examined how Stoicism relates to well-being and to the VIA classification in a large sample not selected for Stoic interest. 11,726 adults completed the VIA Survey, the Stoic Attitudes and Behaviours Scale (SABS), and the WHO-5 Well-Being Index. Stoicism correlated positively with well-being (r = .43) and with all 24 VIA strengths and six virtues, most strongly for Stoic Mindfulness and Virtue. Zest was the strongest unique VIA predictor; Beliefs About Happiness and Virtue were the strongest unique Stoic predictors. Stoicism, operationalised philosophically rather than as emotional suppression, predicted well-being over and above all 24 VIA strengths. The findings reconcile contradictory prior literature and position Stoicism as a complementary, practice-oriented framework that may help explain how character strengths are exercised.
Positive affect (PA) is operationalized differently across studies, leaving open whether distinct conceptualizations relate to subjective wellbeing (SWB) similarly over time. Although mainstream wellbeing theory treats PA and life satisfaction (LS) as components of a latent SWB factor, empirical findings on their causal relations remain inconsistent. This study examined whether pleasant versus energized PA show comparable longitudinal associations with LS using random-intercept cross-lagged panel models across nine waves from two national longitudinal datasets, PAIRFAM (N = 12,520) and LISS (N = 17,532). Both PA types showed consistent bidirectional associations with LS, but relationships were stronger for pleasant PA. Cross-lagged effects and time-specific residual correlations were approximately twice as large compared to energized PA. Pleasant and energized PA also differed in their associations with extraversion and neuroticism. These findings suggest that PA indicator choice affects SWB measure validity, with implications for positive psychology interventions targeting SWB.
