To analyze the epidemiological patterns of comorbidity of anxiety symptoms and depression symptoms among middle and high school students in Zhejiang Province and to provide evidence for making strategy and evaluation of intervention.

Through a multi-stage sampling design, 28 043 students from 376 schools in 30 counties/districts were recruited and surveyed using anonymous self-administered questionnaires in classrooms under the supervision of trained staff between April and June 2022. Anxiety symptoms were assessed using generalized Anxiety Disorders 7-Item Scale, and depression symptoms were assessed using Patient Health Questionnaire 9-Item Depression Scale. A total of 27 004 students were included in the final analysis.

The overall prevalence of comorbidity of anxiety symptoms and depression symptoms was 11.54% (95%CI: 10.90%-12.19%), higher among girls (15.42%, 95%CI: 14.47%- 16.38%) than boys (8.05%, 95%CI: 7.43%-8.67%) (P<0.001), higher among students living in rural areas (12.35%, 95%CI: 11.49%-13.22%) than those in urban areas (10.06%, 95%CI: 9.27%-10.86%) (P<0.001). The prevalence of comorbidity of students attending middle school, academic high school, and vocational high school was 11.73% (95%CI: 10.82%-12.64%), 12.49% (95%CI: 11.20%- 13.79%), and 9.98% (95%CI: 8.68%-11.27%), respectively (P=0.025). The prevalence of comorbidity was higher among students in divorced/widow/separated families (16.64%, 95%CI: 14.86%-18.43%) than those in intact families (10.82%, 95%CI: 10.14%-11.50%) (P<0.001). The wealthier the families, the lower the prevalence of comorbidity (P<0.001). The prevalence of comorbidity was higher among cigarettes smokers in the past 30 days (21.70%,95%CI: 18.24%- 25.16%) than non-smokers (11.13%, 95%CI: 10.51%-11.76%), higher among alcohol drinkers in the past 30 days (19.36%, 95%CI: 17.58%-21.14%) than non-drinkers (10.05%, 95%CI: 9.43%- 10.68%), higher among students engaging in physical fight in the past 12 months (18.42%, 95%CI: 16.75%-20.09%) than those without physical fight (10.45%, 95%CI: 9.81%-11.10%). The more frequently students engaged in physical exercise, the lower the prevalence of comorbidity (P<0.001). The poorer the academic performance self-reported, the higher the prevalence of comorbidity (P<0.001).

More than one-tenth of middle and high school students in Zhejiang Province have comorbidity of anxiety symptoms and depression symptoms, and more attention should be paid to adolescent mental health.

Anxiety; Depression; Comorbidity; Middle and high school students