Research shows why memories are delayed in people with PTSD

Posted on: October 5th, 2017 by sobrietyresources


By David Heitz


Most people who live with PTSD have encountered something so awful it can be difficult for others to even imagine.


That leads to resentment by the person living with PTSD. Far too many people with PTSD reach a point of anger and fear and, with nobody supporting them, turn to drugs and alcohol in an attempt to medicate the pain.


To “just shut everything off in my head” is what people with PTSD often say they long for.


Do you feel like nobody understands the trauma you have been through?


Scientists do, and they are working every day to improve the lives of people living with PTSD.


In fact, a new scientific discovery may shed light on why people with PTSD react the way they do, months, years, decades later, to the terrifying event or events that they experienced.


The study, by scientists in Canada and India, was performed on rats. It showed the hippocampus area of the brain, important to regulating emotions and memory, shrinks after a single traumatic event. The amygdala, meanwhile, also important to memory and emotions, becomes hyperactive.


The result? An explosively angry person. However, sometimes these symptoms do not surface until about 10 days after the traumatic event.


The reason? Memories of the trauma initially were squashed, perhaps due to the shrinking hippocampus.


A hyperactive amygdala and a shrinking hippocampus


What does it all mean?


“The work pinpoints key molecular and physiological processes that could be driving changes in brain architecture,” the National Centre for Biological Sciences reported in a news release. (1)


The center’s Sumantra Chattarji, who also performs research at the institute for Stem Cell Biology, led a team that discovered how the amygdala explodes with electrical activity even 10 days after a traumatic event.


“This activity sets in late, occurring ten days after a single stressful episode, and is dependent on a molecule known as the N-Methyl-D-Aspartate Receptor (NMDA-R), an ion channel protein on nerve cells known to be crucial for memory functions,” according to the news release. “Changes in the amygdala are linked to the development of Post-Traumatic Stress Disorder (PTSD), a mental condition that develops in a delayed fashion after a harrowing experience.”


The amygdala is a group of nerve cells in the shape of an almond. It is located deep inside the brain’s temporal lobe.


Because of the delayed effects associated with PTSD, victims of crimes and other traumas often are doubted when reporting the experience — to friends, family…even police.


When a victim of any kind of harrowing event feels nobody is listening, the odds of turning to drugs and/or alcohol skyrocket.


Drinking and PTSD – like a beer and a cigarette


On its website, the Veterans Administration explains why alcohol and PTSD seem to go hand in hand.


“People with PTSD are more likely than others with the same sort of background to have drinking problems. By the same token, people with drinking problems often have PTSD,” the VA explains. (2)


“Those with PTSD have more problems with alcohol both before and after getting PTSD. Having PTSD increases the risk that you will develop a drinking problem.”


This is why the very last thing anyone who cares about a person with PTSD should ever do is doubt the magnitude of their trauma.


But people inevitably do, unaware of the damage they are causing. People with PTSD don’t “make up” what happened to them. The kind of chronic anger, fear and paranoia that people with PTSD often exhibit cannot be faked.


It’s why research like Chattarji’s is so important. What if we could “shut the brain off,” like people with PTSD often long for, without booze or drugs like benzodiazepines (Xanax, Ativan), which work on the brain the same way as booze?


First, we need to understand what happens in the brains of people with PTSD.


“We showed that our study system is applicable to PTSD. This delayed effect after a single episode of stress was reminiscent of what happens in PTSD patients,” says Chattarji. “We know that the amygdala is hyperactive in PTSD patients. But no one knows as of now, what is going on in there,” Chattarji said in the news release.


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Amygdala becomes lightning rod as hippocampus shrinks


Chattarji and colleagues showed that after the single traumatic event, the amygdala in the rats grew new connections, known as synapses. It’s these connections that conduct the electricity.


“Most studies on stress are done on a chronic stress paradigm with repeated stress, or with a single stress episode where changes are looked at immediately afterwards – like a day after the stress,” said Farhana Yasmin, one of the Chattarji’s students, in the news release. “So, our work is unique in that we show a reaction to a single instance of stress, but at a delayed time point.”


The researchers have pinpointed some promising new therapies for blocking the delayed effects of PTSD after an event. Medications would work with receptors in the brain to accomplish this, but much more research is needed before such a medication would ever become reality. Still, it’s a groundbreaking discovery.


Previous work by Chattarji had concluded that a single traumatic event had no immediate impact on rats. Thus, the observations of the hippocampus and amygdala 10 days later is significant.


PTSD just doesn’t go away that easily.


In an interview with the Canadian Broadcasting Company, or CBC, Chattarji said timing is key to effective treatments. Researchers believe the receptor can be turned off from a day up to a week after the traumatic event.


“Since NMDA receptors are needed for forming memories — a generic blocking will indeed be a problem,” Chattarji said. “That is why we cannot simply block this receptor in anticipation of a traumatic experience, because that may impair the formation of other memories as well.

“However, at the time of the trauma, having the blocker on board would help prevent that experience from becoming of the source of subsequent emotional symptoms in the amygdala.

“So, it is a fine balance.” (3)


The takeaway: Don’t let the trauma you survived kill you later


If you survived something traumatic – the death of a parent, domestic abuse, rape, incest, military combat, attempted murder or some other assault – seek professional help.


This research offers early scientific indicators of what we already know anecdotally – memories of traumatic experiences can be delayed, sometimes for a year or even longer.


If you encountered a recent life event that perhaps only registered “disturbing” on your internal trauma scale, the incident may have been far worse than you originally remember. You may even remember more later.


Cautions the VA, “Women who go through trauma have more risk for drinking problems. They are at risk for drinking problems even if they do not have PTSD.


“Women with drinking problems are more likely than other women to have been sexually abused at some time in their lives. Both men and women who have been sexually abused have higher rates of alcohol and drug use problems than others.”


This is why it is critical to stop drinking. Drinking is like throwing gasoline on a fire for people with PTSD. Oddly enough, the benzodiazepines used to treat PTSD affect the brain exactly the same way. These drugs can be incredibly dangerous over time.


The best way to find lasting recovery is to replace bad habits and ineffective ways of coping with triggers with effective ones. Good treatment centers will offer the assistance of counselors who will help you do that.




  1. Krishnan, A. (2016, Dec. 28). The Late Effects of Stress: New Insights into how the Brain Responds to Trauma. National Centre for Biological Sciences. Retrieved Oct 4, 2017, from


  1. S. Department of Veterans Affairs. (2015, Aug. 15). National Center for PTSD: PTSD and Problems with Alcohol Use. Retrieved Oct. 4, 2017, from
  2. Mortillaro, N. (2016, Dec. 30). New research may offer hope for post-traumatic stress treatment. Canadian Broadcasting Company (CBC). Retrieved Oct. 4, 2017, from


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