A randomized controlled trial of an online mindfulness program for adolescents at risk for internalizing problems

The purpose of this randomized controlled trial was to test the effects of an online, coached mindfulness intervention on momentary negative affect (mNA) for youth with high levels of trait negative affectivity.

Participants were 111 youth ages 12 to 17 years old (M = 14.17, SD = 1.60). Youth self-identified as 68% female, 29% male, and 4.5% gender diverse; 54.55% identified as White; 31.82 reported being Hispanic/Latinx. Participants were selected for having high levels of trait negative affect and were randomized to receive either the mindfulness program or no intervention. We used ecological momentary assessment to measure stress and emotions and to derive measures of mNA comprised of stressor-independent and stressor-reactive negative affect. The ecological momentary assessment protocol involved participants completing a short survey/diary entry on Qualtrics four times per day for 5 days. Internalizing symptoms were assessed with the Patient Health Questionnaire-8, Generalized Anxiety Disorder-7, and the Screen for Child Anxiety Related Disorders.

The mindfulness intervention resulted in a significant reduction in stressor-reactive negative affect (t = 2.001, df = 96, p = .048; Cohen's d = .40), but not stressor-independent mNA or overall mNA. Additionally, reductions in stressor-reactive negative affect significantly correlated with changes in internalizing symptomatology (standardized β = .26, p = .032).

These results indicate that among youth with high levels of trait negative affectivity, a relatively affordable and accessible digital mindfulness program significantly reduced stressor-reactive negative affect. The absence of an effect on stressor-independent or overall average mNA suggests some specificity of the effects of mindfulness to stressor-reactive negative affect in an at-risk sample of adolescents. (PsycInfo Database Record (c) 2025 APA, all rights reserved).