Memory problems are universal in PTSD and come in several forms including:
1) Formation of traumatic memories.
2) Amnesia for all or part of your trauma.
3) Difficulty storing new information.
4) Difficulty finding words.
Obviously, memory problems interfere with learning, especially in a school or work setting. Verbal memory (remembering what you hear) seems to be more strongly effected than visual (remembering what you see or read). Further damage to speech areas in the cortex can also lead to a type of aphasia (difficulty finding the right word) when you speak.
A lot of research had been done on these problems, and it all points to a biological cause— the high levels of noradrenalin and cortisol present in acute PTSD. In previous blogs, I’ve mentioned that these chemicals cause damage to the brain, and this is the cause of memory problems.
Memory problems can occur in both laying down new memories and retrieval. Noradrenalin strengthens the storage of new memories, but cortisol only helps in storing emotionally charged events and interferes with laying down more neutral material, like schoolwork. Cortisol also damages the hippocampus, which then causes problems with memory recall.
How stress chemicals effect memory:
1)Excess cortisol shrinks the hippocampus. This area of the brain normally helps you catalogue, store, and retrieve normal memories. But when you’re under severe stress, the hippocampus is less able to lay down new memories or retrieve them.
2) Excess noradrenalin activates the amygdala, an area responsible for negative emotions like terror, rage, and despair. The overactive amygdala increases your sense of fear, increases startle response, and aids in the storage and retrieval of traumatic memories.
3) Low and high levels of noradrenalin effect the prefrontal cortex (PFC) differently. Normally the PFC calms down the amygdala, inhibits distractions, and helps you pay attention and plan. With a mild increase in noradrenalin, the PFC actually works better. But higher levels block it. Then you can’t inhibit either the amygdala’s negative emotions or other distracting input.
4) Though not as well understood, stress chemicals also activate the amygdala, which grows larger, lays down traumatic memories, and intensifies your negative emotions such as fear, anger, and despair.
5) Stress chemicals also cause damage in areas of the cortex responsible for speech. This plus hippocampal damage may explain problems finding words.
TRAUMATIC MEMORIES are different from normal memories because they’re stored through the amygdala not the hippocampus. This means that traumatic memories:
1) Are more strongly engraved into your brain.
2) Can be difficult to purposefully recall.
3) Can be fragmented, disorganized, and difficult to describe.
4) Can be intrusive and difficult to block.
5) Are recalled abruptly and unintentionally when you are exposed to a trigger.
6) Can be traumatizing in themselves and cause the release of more stress chemicals, which further strengthen the traumatic memory.
Summary Chart of Memory Problems and their Causes:
Some theories suggest a greater secretion of noradrenalin when the stressor involves DEFENSE, and a greater secretion of cortisol when the stressor involves DEFEAT. If you study the chart above, you can see how this could explain the difference in symptoms seen, for example, between veterans traumatized while defending themselves and children traumatized by abuse.
Memory problems can feel overwhelming, but the good news is the brain can heal. Once the cortisol levels go back to normal, the hippocampus can rebuild itself. And once the chemistry recovers in the prefrontal cortex, it gradually returns to normal, improving focus and attention, and calming down the amygdala and it’s negative emotions.
Turning off the stress chemicals:
You have to reset your sympathetic nervous system to reduce the stress chemicals injuring your brain. See my blog on Treating Hyper-Arousal for all the details about initial treatment of an overactive sympathetic nervous system. It discusses medications like Prazosin to block the effects of noradrenalin. My blog on Sleep Disorders in PTSD mentions Gabapentin, which may help to stabilize the amygdala’s overgrowth and overactive emotional response. The Stellate Ganglion Block is a newer approach that uses a nerve block to reset the sympathetic nervous system and decrease the release of stress chemicals. And finally support dogs can provide calming and naturally tune down your defensive system.
Rebuilding the damaged parts of your brain:
MRIs of veterans with PTSD show an enlarged amygdala (which controls negative emotions) and a shrunken hippocampus (the memory center of your brain), as well as shrinkage in other areas involved in focus and attention. But once the stress chemicals are reduced, the brain can grow new cells. Omega-3 fatty acids normalize the amount of BDNF (brain derived neurotrophic factor), which encourages the growth of new nerve cells, especially in the hippocampus. Meditation is also proven to increase nerve cell growth in areas that involve focus and attention, and all of the Antidepressants normalize BDNF–encouraging nerve growth–and regulate the chemistry of the prefrontal cortex, which stabilizes the amygdala.
It’s terribly frustrating when your brain doesn’t work, when you can’t remember what you learned, can’t find the words, or get blindsided by a flashback. But once you reduce the stress chemicals, you can help rebuild your brain and improve both your memory and your emotional control.