Adolescents in a residential school for behavior disorders have an elevated mortality risk in young adulthood.

Background: Conduct problems during adolescence are associated with an elevated mortality risk. This study investigated the mortality rate, causes of death, and changes over time in a Finnish residential school (RS) population.

Methods: All adolescents (N = 885, M/F = 594/291, age mean 15.2 years at baseline) residing in the RS system in 1991, 1996, 2001, and 2006 and matched controls were included in a register-based study with a follow-up time of up to 22 years.

Results: The all-cause mortality rate for people with an RS background was 6.7 % compared to 1.0 % in the controls (Hazard Ratio HR = 6.95, 95 % 4.66-10.37, p < 0.001). 8.1 % of the RS boys had died compared to 2.2 % of the girls (HR = 2.2, p = 0.02). The HR for substance-related death was 24.31 (95 % CI 9.3-65.53, P < 0.001), for suicide 7.23 (95 % CI 3.24-16.11, P < 0.001) and for other external causes 5.45 (95 % CI 2.41-12.36, P < 0.001) compared to controls. Mortality peaked among RS boys at approximately 25 years, whereas for girls it peaked after 30 years.

Conclusions: Adolescents with severe disruptive behavior problems have a seven-fold risk for premature adult-age death compared to matched controls. The most common causes for death were avoidable, substance-related followed by suicide. Effective treatment of mental and substance use related problems during and after the placement is needed to reduce mortality.