Acceptability and Preliminary Effects of a Mindfulness Mobile Application for Ruminative Adolescents.

Rumination is a transdiagnostic risk factor that appears to be reduced through mindfulness interventions. However, mindfulness mobile apps have not been tested for their effects on rumination, especially among adolescents. Thus, we aimed to test the acceptability and effects of a mindfulness mobile intervention among ruminative adolescents using a within-subjects pretest/posttest design. Participants were 80 adolescents ages 12-15, selected for moderate-to-high rumination (M age = 14.01, SD = .99; 46.2% girls; 86.25% White; 3.75% Hispanic). We asked adolescents to use our mindfulness app 3 times per day for 3 weeks. Participants and parents completed questionnaires at baseline, post-intervention, and 6 and 12 weeks later. Acceptability was assessed by tracking app use and asking adolescents and parents to report on their experiences post-intervention. We assessed repetitive negative thinking (i.e., rumination and worry) and internalizing symptoms via self- and parent-report. The intervention demonstrated acceptability, and there were significant reductions in rumination, worry, anxiety and parent-reported internalizing symptoms post-intervention. Effects on rumination, anxiety and internalizing symptoms persisted throughout the 12-week follow-up with large effect sizes using an intention-to-treat approach. Thus, a brief mindfulness mobile app intervention appeared to be both engaging and helpful in reducing negative repetitive thinking and internalizing symptoms among ruminative adolescents. It will be important to test this intervention in a randomized controlled trial to control for effects of time and attention.