PTSD - What is it?

Excerpted from Mark I. Nickerson and Joshua S. Goldstein's book "The Wounds Within: A Veteran, a PTSD therapist, and a Nation Unprepared (2015).

Psychological trauma is physical.  Brain scans show that the memory-related hippocampus in the brain actually shrinks in people with PTSD, but grows again after psychotherapy to resolve PTSD.

PTSD symptoms result from the incomplete processing of memories in the brain.  With traumatic experiences, memories do not get stored in the brain in the same way that normal memories get stored.  The emotional parts of the brain hijack the process, for reasons that make sense at the moment, and normal processing shuts down.  Memories get put aside intact.

The reason that traumatic experiences hijack normal memory formation is that the emotional parts of the brain take over in terrifying situations and the logical thinking parts shut down.  Traumatic situations activate the middle part of the brain—the part that involves motivations, emotions, and drives.  The amygdala responds to danger by activating the body’s survival response system.  In this state, the normal processing of memories becomes a casualty since it is not a priority at the moment.  The brain shuts away the disturbing information, without taking time to process it, and continues to function without becoming overwhelmed by distressing thoughts and feelings.  Months or years later, the experiences that have not been processed and integrated into the memory, eventually work their way to the surface as the intrusive symptoms of PTSD.

The result of incomplete processing is the mind and body continue to react as if the trauma is still happening in the present.  Bilateral stimulation (BLS) aka EMDR therapy can help complete the processing and integrate the traumatic memory with long term memory, thus making the memory a past memory.