Neurobiology of Impulsivity and Aggression as Substrates of Suicidal Behavior: A Narrative Focus on the Involvement of Serum Lipids

Abstract

Previous incidental findings of an increase of suicidal risk among subjects with low cholesterol levels have drawn attention to the role of lipids in suicidal behavior. To date, multiple lines of evidence acquired from clinical studies have confirmed an association between low cholesterol levels and suicidal behavior, but the involvement of dimensional traits including impulsivity and aggression in this association remains elusive. In this narrative review, we aimed to address and synthesize the literature regarding the involvement of lipids in the neurobiology of suicidal behavior and its underlying psychological substrates, impulsivity and aggression. An electronic database search was performed using different combinations of relevant keywords. Both preclinical and clinical studies matching the scope of this article were reviewed and filtered through an inspection of the abstracts to recruit the most suitable articles that contributed essential and substantial findings to the literature. Although subject characteristics and study designs vary across studies, current research has demonstrated that impulsivity and aggression might have shared neurobiologic substrates involved in altered serotonergic neurotransmission. Despite the association between low serum lipid levels and suicidal behavior being well documented, the involvement of lipid subtypes in the pathophysiology of impulsive and aggressive traits remains elusive. Further work is warranted to recognize the roles of lipids in neuronal membrane functions and serotonin metabolism, promote a greater appreciation of identifying biomarkers that could be used to determine at-risk individuals, and develop potential interventions to disrupt the pathogenesis of behavioral phenotypes of suicide.

Neurobiology of Impulsivity and Aggression As Substrates of Suicidal Behavior: A Narrative Focus on the Involvement of Serum Lipids

“…To date, numerous neurobiologic models have been postulated to elucidate the etiology of suicidal behavior, and the stress-diathesis explanatory model has been developed to reveal the complex interplay between neurobiologic factors that possess a susceptibility to suicide such as genetic risk variables, altered serotonergic function, and psychosocial stress responses potentially leading to suicidal behaviors (1,3). This model suggests that vulnerable individuals give abnormal or exaggerated responses to otherwise neutral stimuli (4). Furthermore, advanced neuroimaging techniques have enabled researchers to examine this model regarding the association between brain regions and neurochemistry in emotional, cognitive, and behavioral components of suicide (5).…”