JMIR Publications

ABSTRACT

Background:

Adolescents with depressive symptoms are at increased risk of social functional impairments and more likely to develop major depressive disorder. Digital interventions offer advantages such as high accessibility, especially for adolescents. However, evidence on the effectiveness of web-based psychological interventions in alleviating adolescent depressive symptoms remains limited.

Objective:

This study aims to develop a brief web-based psychological intervention tailored to the developmental and psychological characteristics of Chinese adolescents and to evaluate its effectiveness and influencing factors.

Methods:

In a double-blinded, 2-arm randomized controlled trial, adolescents aged 12-18 years with depressive symptoms were recruited from high schools in China. Eligible participants were randomly assigned in a 1:1 ratio to the intervention group (n=212) or the control group (n=224). The intervention group received a brief web-based emotional cognitive training program, and the control group received a web-based psychoeducation program. Participants received a 4-week intervention. Nonprofessional helpers provided minimal support through text messages or phone calls. The primary outcome was depressive symptom severity. Secondary outcomes included remission rate of depressive symptoms, change scores of anxiety symptoms, suicidal ideation and resilience. Data were collected at baseline, postintervention, 1- and 3-month follow-ups. Statistical analyses included repeated measures analysis of covariance (ANCOVA), chi-square tests, and mediation analysis.

Results:

Two-way repeated measures ANCOVA revealed a significant time effect (F3,1465=85.597, P<.001, 2p=0.150) in depressive symptom severity, with significantly lower scores at T1, T2, and T3 compared to T0 (all P<.001). No significant group effect (F1,1465=3.524, P=.06, 2p=0.002) or group-by-time interaction (F3,1465=2.376, P=.07, 2p=0.005) in depressive symptom severity were observed. Post hoc exploratory analysis revealed that among adolescents with anxiety symptoms, the intervention group had higher remission rate of depressive symptoms at postintervention than the control group (χ21=4.303, P=.04, number needed to treat [NNT]=7.92, risk ratio [RR]=1.41). Furthermore, the intervention group demonstrated a significantly greater improvement in the interpersonal support dimension of resilience at postintervention compared to the control group (least squares mean differences [LSMD]=1.78, 95%CI 0.54 to 3.01, P=.005). Mediation analysis indicated that the intervention improved depressive symptom remission through enhancing the interpersonal support dimension of resilience at postintervention (indirect effect=0.08, 95% CI 0.02 to 0.14).

Conclusions:

The brief web-based psychological intervention did not significantly differ in reducing depressive symptoms from web-based psychoeducation during the 3-month follow-up period. In subsequent post hoc exploratory analysis, we found that brief web-based psychological intervention was effective for adolescents with depressive symptoms who had concurrent anxiety symptoms, and this effect was mediated by interpersonal support. These findings provide new insights into identifying the target population suitable for brief web-based psychological interventions and inform the development of tailored interventions in the future. Clinical Trial: Chinese Clinical Trial Registry ChiCTR2400090235; https://www.chictr.org.cn/showproj.html?proj=243991.