Post-Traumatic Stress Disorder (PTSD) is a severe type of anxiety that arises following a traumatic event. Treatment may require a combination of psychotherapeutic methods and medications. The disorder can cause significant impairment of functioning, as well as physiological changes in the brain’s structure and function, and this can have a complex effect on memory formation, processing, and recall.
Once known as shell shock, PTSD is commonly associated with soldiers who have lived through combat situations. In reality, the disorder can affect anyone after a traumatic event that involves a perceived threat to one’s physical or psychological integrity. Possible traumatic events associated with PTSD also include rape, chronic disease, physical or psychological abuse, and natural disasters. A form of anxiety disorder, PTSD is linked to an array of symptoms, such as insomnia, hyper-vigilance, hyper-arousal, flashbacks of the traumatic event, and persistent avoidance of any stimulus that may be linked to the trauma. Feelings of isolation, numbness, or anger may also be experienced.
Intense fear triggers the sympathetic nervous system into action, and this releases hormones and chemicals to prepare the body for a fight or flight response. This process also activates the amygdala, part of the brain's limbic system, that is involved with processing memories linked to emotional reactions. Emotion-laden memories are easily accessible for recall. Persistent re-experiencing of trauma, and heightened emotional memories of traumatic events, are characteristic of PTSD. Fragmented trauma recall is one of the possible effects of PTSD on memory.
The effects of PTSD on memory are complex. Medical studies indicate severe psychological trauma can cause physiological changes in the brain. The medial prefrontal cortex is thought to play a part in short-term memory. It also has a regulatory and inhibitory action on unsuitable emotions, behaviors, and thought patterns. This brain area appears to be impaired in PTSD. The amygdala is linked to the consolidation of memories, especially those linked to fear, and learned fear responses. This structure is activated in PTSD, eliciting and reinforcing fear conditioning to a stimulus.
Cortisol is a hormone produced by the body in response to stress. PTSD sufferers faced with stressful situations typically release more cortisol than their healthy counterparts. The hippocampus is a brain structure associated with long-term memory and it is highly vulnerable to excess cortisol. Research shows the hippocampus loses volume in some people with chronic PTSD. It is unclear whether this is irreversible, but it can negatively affect learning and memory formation.
Sufferers often experience the multi-faceted effects of PTSD on memory. Antidepressant or anxiolytic medications are sometimes used to help improve symptom control and reduce the impact of PTSD on memory recall associated with traumatic events and the formation of new memories. Other treatments can include cognitive behavioral therapy and eye movement desensitization and reprocessing. A large percentage of PTSD survivors make a full recovery with treatment.