Victims of traumatic brain injury (TBI) may have a significantly elevated risk of suicide relative to those who have not suffered major head trauma.
This year, a retrospective analysis of more than seven million people in Denmark found that the annual suicide rate of individuals with a history of TBI was 41 per 100,000, compared to 20 per 100,000 annually in individuals without prior history of TBI.
Moreover, of the more than 34,000 reported suicides in Denmark, over 10% of individuals suffered from either a mild concussion, a skull fracture, or severe TBI.
Additionally, as the severity of head trauma increased, the suicide risk also rose substantially, with the greatest suicide risk transpiring within the first few months after treatment for head trauma. Bolstering these findings is the fact that the authors of the study controlled for all pre-existing or concurrent psychiatric illnesses (Madsen et al., 2018).
The correlation between head trauma and neuropsychiatric complications has been well documented. Head trauma is associated with a significantly increased risk of unipolar and bipolar depression, schizophrenia, cognitive decline, and mood disorders (Orlovska et al., 2014; Robinson & Jorge, 2002). It is the risks of depression and mood disorders which are of special interest with respect to suicide.
As it turns out, the Danish study substantiates prior findings suggesting elevated suicidal ideation in individuals who sustained TBI. A longitudinal cohort study in Seattle, Washington indicated that 25 percent of TBI victims reported some instance of suicidal ideation, exceeding the general population almost sevenfold (Mackelprang et al., 2014).
Pertinence With Respect to Contact Sports
Such findings are of particular relevance to participants in contact sports, professional or otherwise, particularly given the recent discoveries of chronic traumatic encephalopathy (CTE) in a number of NFL players.
CTE is a long-term manifestation of repetitive instances of TBI. When considering the link between CTE and neuropsychiatric complications, one recent finding involved post-mortem analysis of NFL linebacker Fred McNeill. He was suspected of having CTE after brain scans suggested evidence of tau pathology, an observation validated by a subsequent post-mortem autopsy.
McNeill’s family members indicated that he had suffered from depression until his death in 2015 (Omalu et al., 2018). This discovery offers credence to the suicide/TBI link, as depression is a major contributing factor to suicidal thoughts and actions.
In fact, just this year, 21-year-old American football player Tyler Hilinski committed suicide via a self-inflicted gunshot to the head. An autopsy revealed that this Washington State quarterback exhibited Stage 1 CTE. He was cited as having “the brain of a 65-year-old,” largely attributed to the repeated instances of blows to his head associated with football (CBS Sports, 2018).
Head Trauma is a Risk to Anyone
However, while contact sports come with an elevated risk of head trauma, anyone is prone to the misfortune of head trauma, chronic, severe, or otherwise. Army veterans of the Iraqi and Afghan wars who were diagnosed with TBI have also been shown to exhibit elevated suicidal ideation and attempts compared to those who were not diagnosed (Fonda et al., 2017).
While such findings may be confounded by the high comorbidity of post-traumatic stress disorder (PTSD) in veterans, there is reason to infer that TBI may very well have spiked the numbers even more.
Furthermore, victims of vehicular accidents, concussions, or everyday falls or collisions can be subject to head trauma and all of the corresponding, potential risks its ensues, including long-term alterations to mood.
Each instance of head trauma can have an indelible, incremental mark on compromising neuropsychological well-being.
Possible Neuropathology Underlying the TBI/Suicide Risk
Delving into the potential neurobiology underlying this relationship, it has been found that individuals who suffer from clinical depression following TBI have exhibited functional and structural alterations in the frontal lobe, such as reduced gray and white matter volume in the orbitofrontal cortex, and reductions in density and size of neurons in the prefrontal cortex (Bremner et al., 2002; Drevets et al., 1997).
Alongside depression, suicidal thoughts and actions are driven by regulation of mood and emotions. This involves interactions between the prefrontal cortex and the limbic system (implicated in reward processing). The trauma and contusions associated with TBI can lead to axonal injury and cell death, leading to disruption of these complex interplay between the limbic and prefrontal circuits of the brain.
This neuropathology has been found to manifest through deactivation of prefrontal cortices and elevated activation of limbic structures such as the amygdala. This situation would likely compromise one’s decision-making, while heightening one’s emotional response and impulsivity, a lethal combination which could perpetuate suicidal thoughts and actions (Rapoport et al., 2003).
Responding to This TBI/Suicide Link
While the findings above still do not establish a causal relationship, they do suggest a very strong link between TBI and suicide risk. There needs to be a great emphasis both on preventative measures and early intervention for TBI.
Anyone with a lifestyle placing them at high risk of head trauma, such as a contact sport athlete, a construction worker, of a motorcyclist should wear requisite protective head gear to minimize the threat of head trauma.
Any individual with a previous or recent instance of head trauma should immediately be tested for TBI. Today, there is a blood test approved by the Food and Drug Administration (FDA) to immediately detect TBI: The Banyan Brain Trauma Indicator (Banyan BTI).
The test identifies two biomarkers of TBI: Glial Fibrillary Acidic Protein (GFAP) and Ubiquitin Carboxy-terminal Hydrolase-L1 (UCH-L1), both of which are detectable in blood within hours of sustaining a head injury (Diaz-Arrastia et al., 2014; Papa et al., 2016).
Next, should the blood test come back positive, a team of physiatrists, neurologists, and mental health professionals should work in concert to actively treat the TBI victim, through treating the actual brain contusion, through cognitive rehabilitation, and through neuropsychiatric evaluation for depression, cognitive and/or decision-making impairment, or suicidal ideation.
These patients then need to be followed up to ensure their neuropsychiatric well-being going forward.
The key is early response, and following up by health care professionals to any instance of head trauma, or better yet, to prevent head trauma from transpiring in the first place. Suicide and TBI take thousands of lives annually, and a potentially synergistic comorbidity between the two needs a requisite response. Taking such measures will ensure that victims of TBI can be averted from one potential avenue of casualty, and can continue to live fulfilling lives in the future.
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CBS Sports. (2018, June 26). Washington State QB Tyler Hilinski found to have CTE, ‘brain of a 65-year-old’ after suicide. Retrieved from https://www.cbssports.com/college-football/news/washington-state-qb-tyler-hilinski-found-to-have-cte-brain-of-a-65-year-old-after-suicide/
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