Effects of a Digital Parent-Child Single-Session Growth Mindset Intervention on Adolescent Depression and Anxiety Symptoms: A 3-Arm Waitlist Randomized Controlled Trial (Preprint)

BACKGROUND Depression and anxiety are prevalent among adolescents globally. Parents are the most direct and crucial pillars in supporting adolescents’ mental health, and parental mindsets matter. Yet digital parent-child mindset interventions are rare and understudied. Given promising results from single-session interventions for youth, this study developed and evaluated a parent and child single-session intervention on mindsets of intelligence, failure, and emotion (PC-SMILE) to alleviate adolescent depression and anxiety. OBJECTIVE This study aimed to examine the effectiveness of PC-SMILE in reducing depression and anxiety symptoms among adolescents, compared to the child single-session intervention on mindsets of intelligence, failure, and emotion (C-SMILE) and waitlist control groups. METHODS Classes from each secondary school were randomized to one of three intervention conditions: PC-SMILE, C-SMILE, or waitlist control. Each intervention took approximately 45 minutes online, which included parent-version and child-version. Both parents and students in the PC-SMILE group received the intervention. For the C-SMILE group, only students received the intervention. Students in the three groups were assessed at 3 time points: baseline before intervention, 2 weeks post-intervention, and 3 months post-intervention, while parents were assessed in baseline and 3-month follow-up. Generalized estimating equations were used to test the effectiveness of the single-session interventions. RESULTS A total of 390 parent-child dyads from 7 secondary schools were randomly assigned to either the PC-SMILE intervention group (n = 126), the C-SMILE intervention group (n = 138), or the waitlist control group (n = 126). The intent-to-treat analysis found no significant time*group interaction effects on all outcome measures. However, the results revealed a significant decrease at 2 weeks post-intervention in symptoms of anxiety (P < .001) and depression (P = .042) and hopelessness (P = .017) and a significant improvement in mental well-being (P = .037) and parent-child relationships (P = .003) for the PC-SMILE group, and the enhancement in parent-child relationships sustained at the 3-months follow-up (P = .004). Moderation analysis showed that participants with higher baseline depression and anxiety levels and girls exhibited greater improvements in depression and anxiety symptoms. CONCLUSIONS The PC-SMILE intervention showed preliminary evidence of effectiveness in reducing adolescent anxiety and depression and improving parent-child relationships. Our findings revealed the potential benefits of brief online interventions for adolescents and parents, which may be scalable, destigmatized, and cost-effective alternatives to school-based programs. Future studies should focus on using mixed methods to evaluate outcome, and improve and amplify the effects of single-session interventions for adolescents. CLINICALTRIAL ClinicalTrials.gov NCT05493865 INTERNATIONAL REGISTERED REPORT RR2-10.2196/63220