14 DAY TRIAL // Well, racking your brains does have its consequences. Stress is a big enemy of the brain, as showed by a new research published in the journal of Biological Psychiatry. Military combat implies the experience of an extreme stress, and many ex-soldiers involved in fights are diagnosed with post-traumatic stress disorder (PTSD). The new research linked this condition to several abnormalities in brain structure and function.
"Although it is tempting to conclude that these abnormalities were caused by the traumatic event, it is also possible that they were pre-existing risk factors that increased the risk of developing PTSD upon the traumatic event's occurrence," said co-author Roger Pitman.
The team assessed using MRI (magnetic resonance imaging) the density of gray matter (neuronal mass) of the brains of combat-exposed Vietnam veterans, some with and some without PTSD, and their identical twins not involved in fights. It appeared that gray matter density of the pregenual anterior cingulate cortex (a cerebral nucleus controlling emotions) was lower in veterans suffering of PTSD compared to their non-combat exposed twins.
"This finding supports the conclusion that the psychological stress resulting from the traumatic stressor may damage this brain region, with deleterious emotional consequences," said Pitman.
The new study completes previous researches. "Compelling data from animal research indicates that stress can cause brain atrophy and even neural death in some brain regions. On the other hand, the volume of several brain regions are highly heritable and small brain volumes, presumably related to reduced function, in the hippocampus may increase stress reactivity or impair the capacity for resilience," said Dr. John H. Krystal, Editor of Biological Psychiatry and affiliated with both Yale University School of Medicine and the VA Connecticut Healthcare System.
The results "suggest that volume reductions in [the anterior cingulate cortex] associated with PTSD arise as a consequence of stress exposure rather than emerging as a heritable trait. The extent to which particular genes and environmental exposures interact to shape the development of the brain thus appears to be complex and region-specific,"added Krystal.