Researchers at the VA Boston Healthcare System suggest in a new study that veterans with more severe PTSD may have weaker connectivity in two brain networks.
The study was published in a recent issue of Biological Psychiatry, per a news release from Elsevier.
The release notes that Jeffrey M. Spielberg, PhD, and his colleagues at the VA Boston Healthcare System examined brain networks in veterans with trauma exposure using functional magnetic resonance imaging (fMRI) and graph theory tools.
Graph theory, the release explains, permits examination of the patterns of brain connections, as opposed to examining individual connections.
In their study, the researchers recruited 208 veterans of Operation Enduring Freedom, Operation Iraqi Freedom, and Operation New Dawn, all of whom had experienced a traumatic event. They found that veterans who had more severe PTSD re-experiencing symptoms (eg, flashbacks or reliving the event) showed weaker connectivity in two networks, the release explains.
The first altered network includes the hippocampus and prefrontal cortex, and is involved in providing contextual information. This suggests that perhaps the hippocampus may be overgeneralizing trauma-related memories, and therefore, fails to correctly classify nonthreatening cues as “safe.
The second network, which was identified only in veterans with comorbid mild TBI, includes the basal ganglia and prefrontal cortex, and plays a role in working memory, the release continues.
The release notes that because the veterans studied here had already experienced a traumatic event, this research cannot identify with certainty whether the observed brain network disturbances were present in these individuals before the trauma occurred, or whether they occurred as a result of the trauma exposure.
Future research of at-risk individuals, perhaps examining soldiers before and after military deployment, will be necessary to clarify this point, the release continues.
[Source(s): Elsevier, Science Daily]