The Relationship Between Traumatic Brain Injury and Suicide: A Systematic Review of Risk Factors

Traumatic brain injury (TBI) significantly increases the risk of suicidal ideation (SI) and behaviors due to neurobiological changes, cognitive impairments, and emotional dysregulation. This review consolidates current evidence on the relationship between TBI and suicide, identifying key risk factors and underlying mechanisms, and highlights the need for further research, especially in civilian populations.

Studies were identified from an online search of PubMed, Web of Science, Cochrane Library, Embase, and Scopus databases with studies published from 2014 to 2024. This review has been registered on Prospero (number CRD42024574643).

Factors indicated such as external causes of injury, comorbidities like depression and substance use disorders, and post-TBI symptoms consistently influence suicide risk. Advanced predictive models emphasize the role of psychological symptoms, particularly depressive features, in forecasting SI post-TBI, underscoring the need for targeted interventions and early symptom management.

The seriousness of TBI significantly impacts the probability of SI and suicide attempts (SA). Research consistently shows that patients with more severe TBIs tend to have higher rates of SI and SA. Psychological disorders, such as depression and substance abuse disorders, greatly increase the likelihood of suicidal actions after a TBI. These conditions not only raise the occurrence of SI but also lead to earlier and more regular SA.