School achievement as a predictor of depression and self-harm in adolescence: linked education and health record study.

BACKGROUND Mental disorders in children and adolescents have an impact on educational attainment. Aims To examine the temporal association between attainment in education and subsequent diagnosis of depression or self-harm in the teenage years. METHOD General practitioner, hospital and education records of young people in Wales between 1999 and 2014 were linked and analysed using Cox regression. RESULTS Linked records were available for 652 903 young people and of these 33 498 (5.1%) developed depression and 15 946 (2.4%) self-harmed after the age of 12 but before the age of 20. Young people who developed depression over the study period were more likely to have achieved key stage 1 (age 7 years) but not key stage 2 (age 11) (hazard ratio (HR) = 0.79, 95% CI 0.74-0.84) milestones, indicating that they were declining in academic attainment during primary school. Conversely, those who self-harmed were achieving as well as those who did not self-harm in primary school, but showed a severe decline in their attainment during secondary school (HR = 0.72, 95% CI 0.68-0.78). CONCLUSIONS Long-term declining educational attainment in primary and secondary school was associated with development of depression in the teenage years. Self-harm was associated with declining educational attainment during secondary school only. Incorporating information on academic decline with other known risk factors for depression/self-harm (for example stressful life events, parental mental health problems) may improve risk profiling methods. Declaration of interest None.