Abstract: ObjectiveTo study the prevalence of depression and influencing factors among middle school students in Shanwei City.MethodsStudents were randomly selected from 12 middle schools in Shanwei City by using a twostage stratified cluster sampling method for an anonymous selfreport questionnaire survey. General demographic characteristics, sleep quality, depression, and drug abuse were evaluated by a selfdesigned questionnaire of adolescents' health knowledge, Pittsburgh sleep quality index scale, and the Center for Epidemiological Studies Depression Scale. Data were analyzed using univariate and multivariate logistic regressions.ResultsA total of 3 489 questionnaires were distributed and 3 042 were valid, with an effective response rate of 87.2% (3 042/3 489). The average age of the participants were (16.06 ± 1.83) years.The male to female ratio was 1∶0.94. The average score of the depression scale in the students was (15.23±9.37), and 307 students had the depression symptoms (depression rating score > 28). Depressive symptom detection rate of the students was 10.1%. The rate of drug abuse was 0.8%. Multivariate analysis showed that female, Grade 12, study pressure, family relationships not good and with much conflicts, average and poor relationship with peers, average and poor sleep quality, and drug abuse were risk factors for adolescent depressive symptoms (ORs: 2.10, 1.97, 2.60, 1.77, 3.59, 2.17, 6.55, 7.27, 21.75, 1.46).ConclusionThe middle school students in Shanwei City had certain depressive symptoms. Special attention should be paid to the Grade 12 students with tremendous learning pressure. Mental health education and timely mediating conflicts among students should be conducted to improve their sleep quality and adjust depressed mood to prevent the occurrence of depression.