Post-Traumatic Stress Disorder
Recent Research on PTSD
In the United States, NIMH of NIH and the VA sponsor a wide range of basic, clinical, and genetic studies of
Studies in animals and humans have focused on pinpointing the specific brain areas and circuits involved in anxiety and fear, which underlie anxiety disorders such as PTSD. Fear, an emotion that evolved to deal with danger, causes an automatic, rapid protective response that occurs without the need for conscious thought. It has been found that the body's fear response is coordinated by a small structure deep inside the brain, called the
The amygdala, although relatively small, is a very complicated structure, and recent research suggests that different anxiety disorders may be associated with abnormal activation of the amygdala. One aim of research is to use such basic knowledge to develop new therapies.
The following are also recent research findings:
Animal studies show that the hippocampus - a part of the brain critical to emotion-laden memories - appears to be smaller in cases of PTSD. Brain imaging studies indicate similar findings in humans. Scientists are investigating whether this is related to
short-term memory problems. Changes in the hippocampus are thought to be responsible for intrusive memories and flashbacks that occur in people with this disorder.
People with PTSD tend to have abnormal levels of key hormones involved in response to stress. Some studies have shown that cortisol levels are lower than normal and epinephrine and norepinephrine are higher than normal.
When people are in danger, they produce high levels of natural opiates, which can temporarily mask pain. Scientists have found that people with PTSD continue to produce those higher levels even after the danger has passed; this may lead to the blunted emotions associated with the condition.
Research to understand the
neurotransmitter system involved in memories of emotionally charged events may lead to discovery of drugs that, if given early, could block the development of PTSD symptoms.