Abstract
Traumatic brain injury (TBI) is associated with varied neuropsychiatric sequelae, including elevated risk for later suicidal behaviors (SBs). This chapter provides a qualitative narrative review of hypothesized biological and neurocognitive mechanisms linking TBI to subsequent SBs. The following selective review specifically highlights: (1) Structural and functional alterations to neural circuitry secondary to common head injuries (e.g., concussions or mild TBI) as well as severe or repetitive TBI (e.g., chronic traumatic encephalopathy); (2) Overlap between post-TBI neuropsychological deficits and proposed bio-behavioral indicators of suicide risk; and (3) Potential neurocognitive mediators of the relationship between TBI and SBs, with a particular focus on executive functions involved in self-regulation (i.e., cognitive and affective inhibitory control) and their neural substrates, e.g., corticolimbic, frontostriatal, and frontoparietal circuitry. The chapter concludes with theoretical and practical implications of this shared pathophysiology, based on the reviewed empirical literature.