Traumatic Memory Retrieval in Dissociative Identity Disorder

Have you ever wanted to know just of what a “repressed” memory is and how it is formed?


Suddenly beginning to remember traumatic events from childhood is a hallmark of dissociative identity disorder. Have you ever researched to find out why this is so? I have, and my findings thus far are intriguing. This piece is another branch of the research I have already done on the corpus callosum, the wiring of our brains, but it goes a bit farther.


Please remember, I do not and do not claim to have earned a college degree above that of Associate in Psychology.  I am merely a person living with dissociative identity disorder trying hard to understand herself, and in doing so to hopefully help herself and others.

I have long noticed that many of the people I have met, with a few exceptions, report beginning to experience the flooding back of the terrible memories of childhood trauma in their mid-20s to early 30s. The sudden remembering of trauma always baffled me until I started to read the research available online. I postulated that there was a correlation between brain maturity and this phenomenon, but now I have a sneaking feeling I have found even more evidence that proves I may be right.

As I mentioned in a previous post, I have been taking some exciting classes on the brain in college. I have learned a tremendous amount and am happy to have made some inferences from the things taught in my classes.

The Corpus Callosum

One of these things is the importance of the corpus callosum in the regulation, overall function, and health of the brain. This a region deep in the brain that consists of bundles of nerves that acts like wiring connecting the two sides of our minds. Without going too deeply, these wires cannot work correctly if the myelin, a fatty substance that coats them, is damaged or does not form properly.

There are many reasons and diseases associated with damage to the corpus callosum including and most important for our purposes here, chronic traumatic stress. When a child’s brain is flooded with the hormones that are secreted to make the body ready for the fight, flight or freeze response when danger is perceived have horrible side effects if the child can never return to baseline levels. In other words, if the child continues to feel threatened 24/7 and year after year their little brains are incapable of getting a rest from these vital substances. Over time many of the structures of the brain are damaged including the amygdala, hippocampus and corpus callosum.

There is a significant substance that coats the “wiring” of the corpus callosum called myelin that acts like insulation. Just like with electrical wiring in your home, if the insulation is broken or missing the wiring cannot propagate a signal correctly or may short out.  Chronic stress in early childhood prevents the brain from achieving full myelination, decreasing the connectiveness between the two hemispheres of the brain.

Hang Onto Your Hats

What follows next in this piece will put together many of the pieces of the puzzle I have been missing for so long.

I have uncovered research that explains why people who live with DID or any other dissociative or severe mental illness report they cannot remember their childhood abuse until later in life. This research is scattered here and there among the many scientific papers on the Internet, and that is probably why no one until now has pulled it all together.

Brain Structures Called Ventricles

There are structures in the brain known as ventricles which contain cerebral spinal fluid (CSF). Made up of four primary structures, the lateral ventricle is the one which caught my attention. It is here (and a few other places as well) in the choroid plexus that the cerebral spinal fluid is manufactured.

CFS is vital to the working of our brains, as it circulates and removes the waste products produced in metabolism by the brain cells kind of like the way our intestinal system and kidneys remove waste products from our body. Without this circulation, our brains would become overwhelmed with waste and would die. Interestingly what has many structures of the brain that can be affected, the corpus callosum is one of the first to be changed. A breakdown of the circulation of CFS will cause it to thin and shrink.

Thinning and shrinking of the corpus callosum means that the wiring between the two hemispheres becomes inefficient and thus there is a breakdown of communication between them.

I believe this is the basis of many major psychiatric disorders such as borderline personality disorder, bipolar disorder, schizophrenia and major depression.

What’s That Got To Do With Anything?

Okay, you may be thinking, but what about suddenly remembering traumatic memories from childhood?

The number of fibers (wires) in the corpus callosum are fixed at birth. However, they grow thicker and thinner in different stages of life. These changes occur because of myelination (adding new insulation) and pruning (getting rid of the extra connections we do not need).

Patience! Patience!

Now please be patient with me, and I promise I will get to the point.

The posterior (back) of the corpus callosum changes in size with age as the myelination and pruning activities of the brain change.  On average, they increase with increased myelination and decrease with pruning.

Check out the following breakdown of how our brains change over time from birth to old age. The ages are approximate as every human’s brain matures at a different rate dependent heavily upon genetics.

A Breakdown of Brain Maturity

Birth to 6 years—Humans are born with more neurons (wiring) than we will ever need to help us interpret the world we have just been born. The first three years of life are when we experience the most increase in brain activity as we learn to survive outside the womb.

Age 7-16 years—Our brains experience more significant growth in the anterior (front) region of the corpus callosum in a wave of development. This development could be because of a growing ability to use language and speech.

Age 17-20+ years— Although our brains have been cutting away unused and unneeded brain cells for many years, pruning of excess neurons (brain cells) begins in earnest and increases.

Age 20- 40+ years—a plateau of pruning and growth is reached. Our brains have reached a point where they are most fully developed. Brain maturity in most people is achieved here, and It is at this stage that connectiveness between neurons and the hemispheres of the brain become fully developed and rich.

During this stage is the point where I believe many who live with dissociative identity disorder begin to remember the severe trauma they experienced as children.

Let Me Ask You to be Patient With Me Just a Little Longer!

I have stated in a previous post that the left hemisphere is responsible for interpreting the world about us, and the right for understanding what is being explained. The left hemisphere is the spokesman for the brain and right acts like its silent partner.

So, the left hemisphere is called the interpreter. (Duh)

As I have said before, they have done experiments with people who have had their corpus callosum (wiring) cut between the two hemispheres of their brain to help end severe seizure activity. The results were stunning.

In one experiment they used headphones and told the person in their right ear (the right hemisphere because they have no communication to the left) to stand up, walk across the room and pick up a pencil. Immediately the person did as they were told. When the scientist asked this subject why he had done so, he reported feeling the need to walk, and he wanted a pencil.

The right brain heard the order and carried it out, but the left hemisphere had no idea that order had been given. To make sense of what the subject had just done, (i.e., standing up and going to get the pencil), the left hemisphere made up a scenario to explain what had just occurred.

The person who had just lied was unaware they had told a fib. To them, the answer they gave was the correct one without a doubt.

The Effects of Severe Childhood Trauma

Severe childhood trauma shuts down the left hemisphere (interpreter) and forces the brain to encode the memories of the event into the right (silent partner) hemisphere. As you may have surmised, if only the right hemisphere holds the memories, the person who experienced them cannot know about their existence, and they are “forgotten.”

In this way life goes on, that is until the person reaches brain maturity when suddenly a new stage of development is reached, and the connections that had been lost due to the trauma are suddenly established. The result is a flood of memories from the trauma the person had experienced in childhood.

The Memories Aren’t Lost

The memories aren’t repressed, they aren’t forgotten and then suddenly remembered. The new connections made between the two hemispheres of the brain have formed.

I think in children who have experienced horrendous and repeated trauma at an early stage in their brain development experience this effect to an even greater extent than do other adults.

The stress hormones that flood their little bodies and are never allowed to return to baseline cause an uptick in loss of connectedness between the two hemispheres of the brain. The reason is that there is a significant dip in the formation of myelin (insulation) surrounding the fibers in their corpus callosum (wiring) at the point (age birth to 6 years) when our brains are just learning how to encode memories and how to survive outside the womb. It is easy to see how traumatic memories can be lost to the “waking self” as they are encoded on the right hemisphere, and the child simply moves on with life not even knowing those events had occurred.

Then when the child who had now developed dissociative identity disorder reaches adulthood (ages 20 – 40) and the connectiveness of the two hemispheres enters a new stage of development. Then these memories that have been filed away in the silent hemisphere of the brain suddenly burst into the consciousness of the left, and we are left scratching our heads and thinking we are crazy.

I know this is new information to many of us in the DID community, but I have included the links to the research I’ve been using to put this together. There is far more to the story to explore, but I wanted to bring you up to date on what I have found so far.

“We are our memories. That’s all we are. That’s what makes us the person we are. The sum of all our memories from the day we were born. If you took a person and replaced his set of memories with another set, he’d be a different person. He’d think, act, and feel things differently.” Brian Falkner




At What Age Is the Brain Fully Developed? (2015). Mental Health Daily. Retrieved from:


Blood Supply, Meninges, and Cerebrospinal Fluid Circulation. The Human Central

Nervous System (2008).

Springer, Berlin, Heidelberg


Luders, E., Thompson, Paul M., Toga Arthur W. (2010). The Development of the Corpus

Callosum in the Healthy Human Brain. Journal of Neuroscience, (30), 30-33



McEwen, B. S., & Morrison, J. H. (2013). Brain On Stress: Vulnerability and Plasticity of the

Prefrontal Cortex Over the Life Course. Neuron79(1), 16–29.


Ventricular System. Retrieved from:





4 thoughts on “Traumatic Memory Retrieval in Dissociative Identity Disorder

  1. Thank you for this article, it helps understanding how memories got back…At the age of 33 I suddenly ‘ remembered’ very much after being severely triggered. However, now I’m 56 and these memories are still covered up, waiting to be processed. They did not come out properly and have been covered up again in absence of any right therapy. Meanwhile DID continues and you wait for help, I hope to get another sudden memory recovery, as this is living very strange” knowing there is very much wrong but not knowing what it is”. Maybe you are not forgotten about what happened, but it remains all in the context of comprehension of the age you were in. So memories could be deformed and changed by age you had during trauma, I believe.


    1. I’m sorry you haven’t been able to find a good therapist. We desperately need more therapists who are trained in DID care. We are working on that very hard.

      The memories of your past are still there, but your system is hiding them for you, just like they always have. What I was trying to explain in this article was an answer to the people who pooh-pooh at repressed memories. Somehow folks have gotten in their heads that we have pushed back these memories or that they have been temporarily forgotten. That isn’t true. The memories have been, well, for lack of better words misfiled. They were encoded and stored in the right hemisphere which is the side that is mute when it comes to expressing what it remembers and how it interprets the world. The left hemisphere is totally unaware these events took place because the memories have been stored in silence.

      Then suddenly our brains reach maturity and make new connections, including between the left and right hemispheres.

      Pow! We remember things that happened years before.

      This puts to rest the false memory syndrome people who claim that memories cannot be so easily forgotten, and thus these memories are false.

      I hope you are able to find the help you deserve soon. It is horrible to be without guidance like that. I’ve been where you are. Peace to you my friend. And thank you for reading my blog. It means the world to me. Shirley


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