Background: Depression and substance abuse are common among patients with traumatic brain injury (TBI). However, previous studies have not examined the temporal association between psychiatric disorders, TBI and suicide.

Objective: To study the prevalence of TBI injury among suicide victims; to determine the association of suicide, psychiatric disorders and TBI severity; and to examine the effect of pre- and post-traumatic psychiatric disorders on their remaining life-time.

Methods: This study examined all suicides (n = 1877) committed during a 16-year period in the province of Oulu, Finland. The information of suicide victims was extracted from the official death certificates and the National Hospital Discharge Registers.

Results: TBI was found in 5.5% (n = 103) of the victims. Compared to the victims without TBI, those with TBI had significantly more hospital-treated psychiatric and alcohol disorders. If TBI subjects had comorbid psychiatric disorders, the time period between TBI and suicide was under 3 years in ∼ 90% of victims in this suicide population.

Conclusions: Seriousness of injury, male gender, older age, being unemployed and presence of psychiatric and alcohol disorders are important to identify as possible predictors for suicidal behaviour in TBI patients. Further studies are required to shed light on interventions aimed at better life management.