Does TBI Increase the Risk of Suicide?

Residents of Denmark who seek medical attention for traumatic brain injury (TBI) have an increased risk of suicide, compared with the general Danish population without TBI, according to a study published in the August 14 issue of JAMA. “Additional analyses revealed that the risk of suicide was higher for individuals with severe TBI, numerous medical contacts, and longer hospital stays,” said lead author Trine Madsen, PhD. Individuals were at highest risk in the first six months after discharge, said Dr. Madsen, who is a postdoctoral fellow at the Danish Research Institute for Suicide Prevention in Hellerup.

Trine Madsen, PhD

A history of TBI previously has been associated with higher rates of self-harm, suicide, and death than are found in the general population. However, previous studies have been limited by methodological shortcomings, such as small sample sizes and low numbers of suicide cases with TBI. Dr. Madsen and colleagues conducted a retrospective cohort study using nationwide registers covering 7,418,391 individuals living in Denmark between 1980 and 2014 with 164,265,624 person-years’ follow-up. Of these people, 567,823 (7.6%) had a medical contact for TBI, which included mild TBI (ie, concussion), skull fracture without documented TBI, and severe TBI (ie, head injuries with evidence of structural brain injury).

Of 34,529 individuals who died by suicide, 3,536 (10.2%) had medical contact for TBI, including 2,701 for mild TBI, 174 for skull fracture without documented TBI, and 661 for severe TBI. The absolute suicide rate was 41 per 100,000 person-years among those with TBI versus 20 per 100,000 person-years among those with no diagnosis of TBI. After accounting for relevant covariates such as fractures not involving the skull, psychiatric diagnoses, and deliberate self-harm, the adjusted incidence ratio was 1.90.

This study “provides insights into the underappreciated relationship between TBI and suicide,” said Lee Goldstein, MD, PhD, and Ramon Diaz-Arrastia, MD, PhD, in an accompanying editorial. “The results … point to an important clinical triad—TBI history, recent injury (especially with long hospital stays), and more numerous postinjury medical contacts for TBI—that serves as a red flag for increased suicide risk,” said Dr. Goldstein, who is affiliated with Boston University School of Medicine, and Dr. Diaz-Arrastia, of the University of Pennsylvania’s Perelman School of Medicine in Philadelphia. The results “indicate that increased suicide risk is relevant across all TBI severity levels, including the far more common mild injuries. Clinicians, health care professionals, and mental health practitioners must take notice of this important information.”

—Glenn S. Williams

Suggested Reading

Goldstein L, Diaz-Arrastia R. Traumatic brain injury and risk of suicide. JAMA. 2018;320(6):554-556.

Madsen T, Erlangsen A, Orlovska S, et al. Association between traumatic brain injury and risk of suicide. JAMA. 2018;320(6):580-588.