Objective To explore the effect of 4-week aerobic exercise intervention on adolescents with depressive symptoms, compare the clinical effects of aerobic exercise intervention and rTMS, and to find the best intervention program for adolescent depression.

Method The 45 adolescents with depression admitted to a specialized mental health hospital in Beijing from April 2023 to September 2023 were divided into exercise group (n=15), transcranial magnetic group (n=15) and control group (n=15). Exercise group intervention program: 4 weeks, 4 sessions/week, 30 min/session of moderate intensity aerobic exercise based on drug treatment. Transcial intervention protocol: 4 weeks, 4 times/week of high frequency repeated transcranial magnetic stimulation (rTMS), stimulation site: left DLPFC, 80% motion threshold, stimulation frequency 10 Hz, each sequence for 4 s, 56 s interval for 20 sequences. The control group had no additional intervention and only had conventional medical therapy. Primary and secondary school Mental Health Diagnostic Test (MHT) and the Hamilton Depression Scale (HAMD) were used to test the degree of depression. The Wisconsin Card Classification Test (WCST) was used to assess patients' cognitive function. Fasting peripheral blood was collected before and after the intervention, and the serum mass concentration change of serotonin (5-HT) was measured by enzyme-linked immunosorbent assay.

Results After the intervention, depressive symptoms of three groups were all significantly relieved. The cognitive function was significantly improved in exercise group and rTMS group, so was the serum 5-HT mass concentration; while no significant changes were found in the control group. There were significant interactions between participants on depression, learning, working memory, cognitive flexibility, and serum 5-HT mass concentration, and the exercise and rTMS groups were significantly better than the control group, but no significant difference between the exercise and rTMS groups.

Conclusion Four weeks of aerobic exercise assisted intervention or rTMS assisted intervention can significantly reduce depressive symptoms in adolescent patients with depression, improve cognitive functions such as learning, working memory, cognitive flexibility and serum 5-HT mass concentration, and the intervention effect is better than pure drug therapy. Aerobic exercise assisted intervention can be an effective alternative to rTMS assisted intervention in adolescent depression.