Objective To examine the association between minor and major mental health impairment in late adolescence and death from suicide and unintentional injuries/accidents in men.

Methods In Norway, all men attend a compulsory military medical and psychological examination. We included 558 949 men aged 17–19 years at the time of military examination in 1980–1999 and followed them up for death from suicide and unintentional injuries/accidents until the end of 2013. We used Cox proportional hazard models to examine the association between the presence of minor and major mental health impairments at examination and death from suicide and unintentional injuries/accidents.

Results Compared to men with no mental health impairment, those with minor mental health impairment was associated with an increased risk of death from suicide (adjusted HR (HR_adj)=1.63, 95% CI 1.39 to 1.92), transport accidents (HR_adj=1.33, 95% CI 1.09 to 1.63), accidental poisoning (HR_adj=2.27, 95% CI 1.79 to 2.88) and other unintentional injuries/accidents (HR_adj=1.54, 95% CI 1.17 to 2.02). In men with major mental health impairment, the risk of death from suicide and accidental poisoning was elevated two times (HR_adj=2.29, 95% CI 1.85 to 2.85) and three times (HR_adj=3.53, 95% CI 2.61 to 4.79), respectively.

Conclusions We found an increased risk of death from suicide and unintentional injuries/accidents in men who had minor and major mental health impairment at age 17–19 years.