Neurobiological Risk Factors for Suicide

Abstract

Context This article reviews neuroimaging studies on neural circuitry associated with suicide-related thoughts and behaviors to identify areas of convergence in findings. Gaps in the literature for which additional research is needed are identified. Evidence acquisition A PubMed search was conducted and articles published prior to March 2014 were reviewed that compared individuals who made suicide attempts to those with similar diagnoses who had not made attempts or to healthy comparison subjects. Articles on adults with suicidal ideation and adolescents who had made attempts, or with suicidal ideation, were also included. Reviewed imaging modalities included structural magnetic resonance imaging, diffusion tensor imaging, single photon emission computerized tomography, positron emission tomography, and functional magnetic resonance imaging. Evidence synthesis Although many studies include small samples, and subject characteristics and imaging methods vary across studies, there were convergent findings involving the structure and function of frontal neural systems and the serotonergic system. Conclusions These initial neuroimaging studies of suicide behavior have provided promising results. Future neuroimaging efforts could be strengthened by more strategic use of common data elements, and a focus on suicide risk trajectories. At-risk subgroups defined by biopsychosocial risk factors and multidimensional assessment of suicidal thoughts and behaviors may provide a clearer picture of the neural circuitry associated with risk status—both current and lifetime. Also needed are studies investigating neural changes associated with interventions that are effective in risk reduction.

Anhedonia as a clinical correlate of suicidal thoughts in clinical ketamine trials

“…First, there is a burgeoning literature on the neurobiology of anhedonia, including linkage to specific neural circuits and neurotransmitters as well as animal models. Given that the neuroimaging literature around suicidal thoughts is comparatively sparse and that animal models of suicide are non-existent (Cox Lippard et al, 2014), this connection to anhedonia can highlight key target areas for future evaluation of treatments for suicidal ideation. For example, anhedonia is often subcategorized into consummatory (hedonic pleasure) and motivational (reward/cost/anticipation) components.…”

Multimodal Neuroimaging of Frontolimbic Structure and Function Associated With Suicide Attempts in Adolescents and Young Adults With Bipolar Disorder

“…Postmortem findings in suicides suggest decreased ventral prefrontal neuroreceptor binding and neurotrophic factors (3, 4). Also implicated are ventral prefrontal connection sites subserving emotion and impulse processing/regulation, including anterior cingulate cortex, insula, thalamus, striatum, and amygdala (5). …”

“…Suicide behavior has been linked to reduced structural integrity and functional fronto-limbic connections in adults in postmortem (6), sMRI, diffusion tensor imaging (DTI), and fMRI studies (5), though few were conducted in bipolar disorder specifically.…”

Are neurocognitive factors associated with repetition of self-harm? A systematic review

“…These factors have the advantage of potentially acting as objective markers, overcoming the biases present with self-reports, for instance reports of past, current or future suicidal intent (Glenn and Nock, 2014). Recent systematic reviews into the brain structural and functional abnormalities associated with self-harm suggest that the main regions involved include the orbitofrontal cortex (OFC), ventromedial prefrontal cortex (VMPFC), dorsolateral prefrontal cortex (DLPFC), and anterior cingulate cortex (ACC), indicating potentially impaired functioning of the prefrontal network (Cox Lippard et al, 2014;Jollant, 2016;Jollant et al, 2011;Van Heeringen et al, 2011;van Heeringen et al, 2014;van Heeringen and Mann, 2014), in addition to other regions including the parietal cortex, some subcortical nuclei and possibly the cerebellum (Gifuni et al, 2016;Jollant et al, 2008a;Richard-Devantoy et al, 2016a).…”