Brain damage can occur as a result of excessive stress. Studies indicate that the hippocampus and stress are associated. Hippocampal volume of war veterans, as well as victims of child abuse or torture has been found to be lower than normal. This is referred to as hippocampal atrophy, which is caused by high cortisol levels. Cortisol is a steroid hormone released during the stress response.
The hippocampus is located in the medial temporal lobe and is part of the limbic system. Limbic system structures play chief roles in emotion, learning, memory and motivation. The hippocampus is responsible for new memory storage and retrieval. Memories are stored in the hippocampus temporarily before being permanently stored in another area of the brain.
Researchers have taken a closer look at the relationship between the hippocampus and stress, more specifically post-traumatic stress disorder (PTSD). PTSD is an anxiety condition resulting from extreme stress experienced during a traumatic event. It has been found that PTSD causes damage to the brain, particularly the hippocampus. This damage results in hippocampal atrophy.
People who have PTSD have problems with memory. Either they have trouble retrieving memories, or the memories are always present. PTSD sufferers experience memories in the form of flashbacks. Fear is experienced as if the event is actually happening again and is triggered by memory. This is why experts believe the hippocampus is affected in PTSD.
The hippocampus is damaged by cortisol because it contains many receptors for the hormone. Cortisol is activated and released by the adrenal gland to get the body ready to respond to a stressful event. It causes an increase in blood pressure, respiration and heart rate. This is a protective mechanism. It is a very useful response.
Repetitive high-level stress can cause PTSD, but not everyone will respond to a traumatic event in this way. It is thought that some people might be more susceptible to it, and the original size of the hippocampus might be a clue. It could be that people born with a smaller hippocampus will be at risk for developing the condition if they are exposed to high level stress, which further explains the connection between the hippocampus and stress.
Problems caused by the hippocampus and stress response can be triggered by exposure to certain types of events. These events are considered to be very traumatic. Examples are automobile accidents, terrorism and natural disasters. Children also get PTSD; their symptoms are different from those of adults.
Treatment is available for PTSD sufferers. Cognitive behavioral therapy (CBT) is most effective and is often used in combination with medication. Selective serotonin re-uptake inhibitors (SSRIs) are drugs that are actually prescribed for depression but have also been found to be helpful in PTSD treatment.
