Mindfulness training fosters a positive outlook during acute stress: A randomized controlled trial.

The tendency to maintain a positive outlook during adversity associates with better health. Interventions that help people cope with stress by maintaining a positive perspective have potential to improve health. Mindfulness interventions show promise for enhancing positive affect in daily life, and developing acceptance toward momentary experiences may help people notice more positive experiences under stress. In a sample of 153 healthy stressed adults (M_age = 32 years; 67% female; 53% White, 22% Black, 22% Asian, 4% other race; 5% Hispanic; collected in 2015-2016), we tested whether mindfulness training, and acceptance training in particular, boosts awareness of positive experiences during acute stress. Participants were randomly assigned to one of three matched 15-lesson remote interventions: (1) Monitor + Accept, standard mindfulness instruction in both monitoring and acceptance; (2) Monitor Only, dismantled mindfulness instruction in monitoring only; or (3) Coping control. After the intervention, positive (and negative) experiences during acute stress challenge (using a modified Trier Social Stress Test) were assessed using a new checklist measure. As predicted, Monitor + Accept participants reported noticing significantly more positive experiences during acute stress than Monitor Only (d = .61) and control (d = .58) participants, whereas the number of negative experiences noticed did not differ by condition. Across conditions, positive experiences during acute stress correlated with daily life positive emotions at postintervention (r = .21). Results suggest that mindfulness training, and acceptance training in particular, can broaden awareness to include more positive affective experiences. This work has important implications for understanding coping and affect dynamics following mindfulness interventions. (PsycInfo Database Record (c) 2025 APA, all rights reserved).