Positive cognitive reappraisal flexibility is associated with lower levels of perceived stress

This study investigates the role of positive cognitive reappraisal (PCR) flexibility and variability in mental health in response to real-life stressors among college students. We employed ecological momentary assessment and intervention through ReApp, a mobile app designed to train and promote PCR. We analyzed data from the intervention group of a randomized controlled trial with a total of 100 participants who used ReApp for three weeks. Stressors due to health problems, uncomfortable environment (e.g., rainy weather, crowded buses, etc.), and lack of time were reported most frequently. Stressors related to the war in Ukraine, fear of the future, exams, and COVID-19 were reported as the most severe. To reappraise these stressors, the participants used mostly acceptance and problem-solving tactics. A key finding is the role of emotional demand–dependent PCR flexibility in mental health. Specifically, the flexible adaptation of PCR tactics in response to stressor severity was associated with a more substantial decline in perceived stress over the study period among participants reporting low tendency to use PCR at the study's baseline (β = − 0.963, p = .016, Cohen's f = 0.26). In contrast, stressor domain–dependent flexibility and contextually independent between-tactic variability had no moderating effect on stress, depression, and anxiety symptoms. This study contributes to the field of emotion regulation flexibility by highlighting the adaptive role of emotional demand–dependent PCR flexibility in mental well-being among young adults navigating real-life stressors and underscores the importance of tailoring interventions based on the emotional demands of stressors.