LAUSR

Objectives While practicing mindfulness can potentially mitigate and prevent mental health problems among adolescents, mindfulness programs delivered in schools do not uniformly lead to uptake of mindfulness practice. This low adherence threatens the internal validity of mindfulness trials and may hinder the alleviation of mental health problems in youth who fail to take up potentially effective techniques. Consequently, it is vital to investigate what predicts uptake of independent mindfulness practice in such interventions. Methods Using path analyses, this study investigates whether social cognitions from the Reasoned Action Approach and initial mental health predict mindfulness practice among 1646 adolescent recipients of the school-based Healthy Learning Mind mindfulness intervention. Results In line with the Reasoned Action Approach, descriptive and injunctive norms, and positive and negative outcome expectations predicted intention to practice mindfulness (R 2  = .37, p  < .001), which in turn predicted different measures of mindfulness practice itself (R 2  = .09–.17, p  < .001). Neither perceived behavioral control nor mental health variables (depressive symptoms, internalization and externalization of difficulties, and resilience: R 2  = .01, p >  .05) were associated with mindfulness practice after the intervention. Conclusion Social norms and outcome expectations are potential intervention targets to increase mindfulness practice motivation and behavior among adolescents.