Recent studies on one of the most important part of he limbic system, the amygdala, found that these little almond shaped organs located within each side of the temporal lobes can actually have a significant impact on future treatment for PTSD (post-traumatic stress disorder) and other anxiety conditions.
In an article released last week, a group of scientist from the University of Iowa described of a female adult patient who had an extremely uncommon condition in which her amygdala was destroyed. The patient was not able to experience fear, even after being placed in situations she once loathe of (haunted house, having snakes and spiders placed near her, watching horror films, and talking about life-threatening things). The researchers believe that the reason for her lack of fear was that her amygdala did not function.
The amygdala is known to play a key role in triggering fear reactions, as various studies have concluded. These studies, however, are done on animals. "This study is the first to show that it is also the case in humans," wrote the authors. Daniel Tranel, Ph.D, senior study author, states that their findings may impact how health care professionals will treat patients with PTSD and anxiety disorder. Tranel wrote:
- "This finding points us to a specific brain area that might underlie PTSD. Psychotherapy and medications are the current treatment options for PTSD and could be refined and further developed with the aim of targeting the amygdala."
- "This past year, I've been treating veterans returning home from Iraq and Afghanistan who suffer from PTSD. Their lives are marred by fear, and they are oftentimes unable to even leave their home due to the ever-present feeling of danger. In striking contrast, the patient in this study is immune to these states of fear and shows no symptoms of post-traumatic stress. The horrors of life are unable to penetrate her emotional core. In essence, traumatic events leave no emotional imprint on her brain."
- "Taken together, these findings suggest that the human amygdala is a pivotal area of the brain for triggering a state of fear. While the patient is able to experience other emotions, such as happiness and sadness, she is unable to feel fear. This suggests that the brain is organized in such a way that a specific brain region - the amygdala - is specialized for processing a specific emotion - fear."
- "Without our amygdala, the alarm in our brain that pushes us to avoid danger is missing. The patient approaches the very things she should be avoiding, yet, strikingly, appears to be totally aware of the fact that she should be avoiding these things. It is quite remarkable that she is still alive."
Justin S. Feinsteinsend, Ralph Adolphs, Antonio Damasio, Daniel Tranel
Current Biology, 16 December 2010. 10.1016/j.cub.2010.11.042
