Stress and the Brain: Neuroimaging and Hope for New Treatments
One exciting area in neuroscience research is the possible discovery of specific brain circuit changes in people with posttraumatic stress disorder (PTSD), which can occur in people who live through natural disasters, wars, violence or other stressors. While this research is relatively new, it may not only show how the brain is affected by stress, but also offer clues to better treatment for PTSD.
At its 2012 annual meeting the Society for Neuroscience, a “nonprofit membership organization of scientists and physicians who study the brain and nervous system,” released several new studies [PDF] about stress and neuroimaging. These studies were funded mainly by governmental agencies from the U.S., Canada, Japan, along with some private foundations. A pharmaceutical firm provided assistance in one study along with the aforementioned funders.
Perhaps the most intriguing study was one from Japan that looked at adolescents who survived the Tohuku earthquake in 2011. This quake measured 9.0 on the Richter scale, killed more than 15,000 people, and destroyed or damaged over 300,000 buildings. The researchers had access to brain scans of healthy teens taken before the catastrophe. Thirty of these adolescents agreed to have their anxiety measured and to have new scans several months after the disaster.
The researchers had two main findings:
- Subjects with “weak” connections on the right front part of their brains before the quake were more likely to have a high anxiety level afterward.
- Subjects with “strong” connections in the front left part of the brain after the incident also tended to have greater anxiety following the quake.
This study is unusual for several reasons. First, it was able to use data from people without a psychiatric diagnosis as a baseline. Second, it could identify which changes in the brain scans occurred after the quake, possibly identifying a physical marker of trauma. Last, the study identified another marker that might identify the risk of developing PTSD before undergoing extreme stress.
Other studies presented focused on possible treatments for PTSD. Neil Fourier, Ph.D, one of the authors, noted that medications are often ineffective and therapy, while useful in symptom reduction and establishing coping skills, does not completely eliminate the “core symptoms.” Fourier found that rats administered ketamine, which is also being investigated as an antidepressant in humans, did not show fear when re-exposed to a stressful situation. Rats that had been administered a placebo, however, remained fearful. The author believes that ketamine may reduce PTSD by “remodeling” part of the prefrontal cortex and in humans may be more effective when used in conjunction with exposure-therapy.
These discoveries may not yield immediate treatments, but they seem to be important milestones in helping those with PTSD. By understanding the pathways in the brain that contribute to recurring anxiety and flashbacks, researchers may be closer to finding ways to successfully ease the symptoms of this disorder. Whether these treatments are medicinal or a form of talk therapy, knowledge of how the brain is working should bring us closer to a more effective treatment.