Biomarker For Depression Symptoms In Patients With Traumatic Brain Injury Potentially Identified

Identification of depression symptoms in those with traumatic brain injury (TBI) may have just gotten far easier. It has been discovered that about half of those with a diagnosed TBI will also experience depression within the next year. According to the Center for BrainHealth at the University of Texas at Dallas, part of the challenge in diagnosing depression symptoms is that there are many similarities between TBI symptoms and those of depression.

"It is very difficult to tell the difference between traumatic brain injury symptoms and depression symptoms," Kihwan Han, PhD., reported.

Han is the lead author of the study regarding the link between traumatic brain injury and depression symptoms and a postdoctoral research associate at the Center for BrainHealth, according to PsychCentral.

By Irais Esparza (Own work Naucalpan de Juárez, Edo. México) [CC BY-SA 4.0 (], via Wikimedia Commons
By Irais Esparza (Own work Naucalpan de Juárez, Edo. México) [Image via CC BY-SA 4.0 (, Wikimedia Commons]

According to News Medical, the study was published November 5 in Frontiers in Neurology: Neurotrauma. The study reports that connectivity-based neuroimaging biomarkers have not been previously studied in other research efforts between traumatic brain injury and depression symptoms. With this study, which involved participants who were at least eight years past the traumatic brain injury diagnosis, there was a marked increase in amygdala connectivity.

The amygdala is the emotional center for the brain. According to Neuroscience Online, the amygdala "is the integrative center for emotions, emotional behavior, and motivation."

According to the published research report, increases in amygdala connectivity ultimately means that it could be a potentially effective neuroimaging biomarker for depression symptoms. The differences in connectivity noted during the study also helped researchers determine whether individuals were demonstrating cognitive depression symptoms, which are related to patterns of thought or affective depression symptoms, which are related to one's general mood.

Fifty-four patients with chronic TBI, including civilians and veterans alike, were involved in the study. The traumatic brain injury itself was caused by any one of a number of factors, including blasts, blunt force trauma, falls, athletic impacts, vehicle accidents, or combinations of any of these. It was found that individuals who expressed mostly cognitive depression symptoms, such as thoughts of guilt, worthlessness, self-dislike, or thoughts of suicide, showed reduced amygdala connectivity with prefrontal cortices of the default mode and cognitive control networks.

Those with mostly affective depression symptoms, which included crying, loss of interest, indecisiveness, and loss of pleasure, showed reduced amygdala connectivity with the brain regions of salience such as the insula, the parietal lobules (which govern attention and focus), and visual networks. While this was a relatively small study, the results of it led researchers to hope that more individualized treatment plans for those with chronic TBI and depression could be developed.

"We look forward to being able provide a more robust picture of how cognitive training may affect behavioral symptoms associated with structural brain change due to injury," said principal investigator Daniel Krawczyk, Ph.D., associate professor of cognitive neuroscience and cognitive psychology at the Center for BrainHealth.

See page for author [Public domain], via Wikimedia Commons
[Image via Public domain, Wikimedia Commons]

The study was funded by the Department of Defense and was designed to examine the effectiveness of strategy-based cognitive training in veterans and civilians who have a traumatic brain injury. The severity of symptoms was variable across the study group; 31 members had moderate to severe depression symptoms while the remaining 23 had mild depression symptoms. Those involved in the study ranged in age from 20 to 60.

All individuals involved were at least six months past their initial TBI diagnosis, but the average length of time since the injury occurred was actually eight years. During that time, patients had no history of any clinically-diagnosed neurological or psychiatric disorders or depression symptoms prior to their injury.

The biggest challenge with those who might have depression symptoms is that depression symptoms vary greatly. As a result, there is a dual challenge when the person with depression symptoms also has a TBI.

Han's future work will include research into whether a reduction in depression symptoms after any cognitive or affective training are associated with any changes in amygdala connectivity.

[Image via Bohlega S, Al Shubili A, Edris A, Alreshaid A, Alkhairallah T, AlSous MW, Farah S, Abu-Amero KK. CC BY 2.0 (, Wikimedia Commons]