Objective  To explore the effect of parental education level on the level of depression in primary and high school students.

  Methods  Using stratified random sampling, we selected 70 628 students aged 10 to 17 years (mean = 14.11 years, standard deviation = 2.37 years) from primary and high schools in 85 districts or counties of 10 provinces/autonomous regions/municipalities directly under the central government for a questionnaire survey with The Center for Epidemiologic Studies Depression Scale (CES-D) and a positive mental characters questionnaire for primary and high school students compiled by the First Department of Basic Education of the Ministry of Education. The survey was conducted between April and July 2011 and eligible information were collected from 47 863 students totally.

  Results  The mean depressive symptoms score was 14.64 ± 10.08 for all the students, with a significantly higher mean score among the boy students than among the girl students (P < 0.001) and a significantly lower mean score among the primary school students (P < 0.001). The overall detection rate of depression was 11.64 % (5 570/47 863) among the students; the detection rates were 9.24 %, 13.52 %, and 13.26 % among primary, junior high, and senior high school students, and the detection rates were 12.42 % and 10.96 % among boy and girl students, respectively. Family atmosphere showed an intermediary role significantly on the correlation between parental education level and the level of depression among the students (t_father = 11.9842, t_mother = 11.1269; P < 0.001).

  Conclusion  Parental education influences, not only directly but also indirectly through family atmosphere, on the level of depression and good family environment is helpful to reduce the incidence of depression among adolescent students.