The Role of Frontolimbic Network in Suicide: A Descriptive Literature Review of Neuroimaging Studies.

Suicide is a complex public health issue characterized by impairments in emotion regulation and cognitive control. Identifying the brain substrates of suicide is critical for developing targeted and effective prevention strategies. Given the central role of the frontolimbic network in affective processing and executive functioning, this review aimed to summarize neuroimaging findings in the frontolimbic network associated with suicidal thoughts and behaviors (STBs). We first reviewed structural and functional neuroimaging studies published over the past decade reporting frontolimbic network changes in individuals with a history of suicidal ideation or attempt. Next, we discussed the role of the frontolimbic network in suicide, progressing from abnormalities in individual brain regions to structural and functional connectivity disruptions within this network. The reviewed literature suggests some convergent frontolimbic network alterations related to STBs. First, structural atrophy of the frontolimbic regions is generally observed, while heterogeneous functional changes exist. The prefrontal deficits in structure and function are right lateralized, aligning with the right-hemisphere dominance in negative emotion processing. Second, the anterior cingulate cortex may serve as a hub of the frontolimbic circuit, enabling the integration and coordination of neural processes between the prefrontal cortex and limbic regions. Finally, the frontolimbic network exhibits a shift from early compensation to late decompensation in individuals with STBs, indicating exhaustion of compensatory mechanisms and loss of top-down control in suicide as the illness progresses. The comprehensive description of frontolimbic network characteristics may advance the understanding of suicide from a network perspective and provide insights into therapeutic targets for suicide interventions.