Teens with depression face 17.5% higher risk of early death — more from accidents than suicide, 30-year study finds

Adolescent depressive symptoms are more strongly associated with early death from external causes — including accidents, unintentional drug overdoses and assault — than from suicide in adulthood, a new study has found.

A research team led by Kim Jin-ho, a professor at Korea University's School of Health Policy and Management, reached that conclusion after tracking 14,320 participants in the US National Longitudinal Study of Adolescent to Adult Health, known as Add Health, from 1994 to 2023 — roughly 30 years. Even after controlling for individual and family background factors, adolescents who experienced more severe depressive symptoms faced a 17.5 percent higher risk of dying before age 50.

The differences became sharper when the researchers broke down causes of death. Deaths from external causes — including traffic accidents, accidental poisoning and assault, as well as drug overdoses — were 29.6 percent more likely among those with greater adolescent depression, the strongest association found in the study. Those in the top quartile for depressive symptoms faced a risk of dying from external causes 2.26 times higher than those in the bottom quartile. By contrast, no statistically significant association was found between adolescent depression and deaths from illness or suicide. The researchers cautioned that the number of suicide deaths in the dataset was small and that this finding should be interpreted carefully.

A pathway analysis found that among all premature deaths, not completing high school (16.0 percent), smoking (10.8 percent) and cannabis use (9.0 percent) were the most influential mediating factors. For deaths from external causes specifically, cannabis use (12.2 percent) and smoking (6.9 percent) emerged as the primary pathways. The findings suggest that depressed adolescents who later turn to tobacco or cannabis face a heightened risk of accidental death or drug overdose.

Kim, who led the study, said the assumption that depression inevitably leads to suicide is a misconception. "There is a policy implication here: we need to look broadly at the many health threats that can arise from poor mental health," he said. He added that responses to adolescent depressive symptoms must go beyond symptom management alone. "An integrated approach that supports substance use prevention, continued education and a stable transition into society is essential. Schools, communities, and education and employment support systems need to work in concert to ensure that emotional difficulties in adolescence do not translate into later health and socioeconomic disadvantages," he said. The findings were published online on June 25 in European Child & Adolescent Psychiatry, a top international journal in child and adolescent psychiatry, and the research was supported by the BK21 Four Program in Precision Health Science Convergence.

If you or someone you know is struggling with thoughts of suicide or self-harm, call the Suicide Prevention Hotline at 109, available 24 hours a day, seven days a week. Please request a translator for English-language services.