Losing your train of thought with traumatic experiences: Is it for the best?

A single traumatic experience can shape the rest of one’s life for better or worse — but more likely for the latter. This idea is certainly disturbing, as almost 70 percent of adults in the United States, or 223.3 million people, have dealt with a traumatic experience such as abuse, violence, or grief. Young adults and adolescents are no exception to these eye-opening statistics, and at least a third of those who experience trauma will develop post-traumatic stress disorder (PTSD) throughout their lives.

Young adults and adolescents are no exception to these eye-opening statistics, and at least a third of those who experience trauma will develop post-traumatic stress disorder (PTSD) throughout their lives

If traumatic experiences are this common, how does the brain process them so that victims can go on to survive and thrive? Scientists across the world are seeking answers to this question to improve our understanding of the brain and develop the most effective therapies to help patients from succumbing to their trauma. 

According to Dr. Darlene McLaughlin, a psychiatrist at Texas A&M College of Medicine, the brain typically deals with traumatic experiences by dissociating from them. A typical example of dissociation occurs when daydreaming, and more serious cases can lead to the development of dissociative and mental disorders. Scientists think that there is only a certain amount of trauma a person can go through before dissociating from an experience, and this threshold varies based on age, genetics, and environmental factors. 

Researchers at the University of Basel in Switzerland have made promising discoveries relating to why certain people are able to dissociate from traumatic memories more than those who aren’t able to. Vanja Vukojevik and her team studied survivors of the Ugandan Civil War and the Rwandan Genocide. They discovered more gene regulation by DNA methylation in both groups of the survivors. Specifically, the survivors had stronger regulation of the gene Ntrk2, which in the past has been linked to memory formation. As a result, those with stronger regulation of Ntrk2 were less likely to develop PTSD, as the increase in regulation alters brain activity in the regions of the brain responsible for memory. Vukojevik and her team hope to continue their study of trauma to understand the intrinsic complexities of the brain. 

Scientists think that there is only a certain amount of trauma a person can go through before dissociating from an experience, and this threshold varies based on age, genetics, and environmental factors.

While Vukojevik studies the effects of trauma on a subcellular level, several scientists are also exploring its effects on the cellular level and in the brain. One of the most notable is Professor Johannes Graff and his team at L’École Polytechnique, who have discovered a group of neurons that are responsible for remembering glimpses of a traumatic memory. In order to find this group of neurons, they pinpointed a phenomenon called fear attenuation, which involves subduing an original memory’s trace of fear with one that has been rewritten and considered to be safer.

The researchers used genetically modified mice with fluorescent proteins that could respond to neuronal activity, and they trained the mice with fear-inducing exercises. They discovered that neurons in the dentate gyrus, a part of the temporal lobe in the brain known for episodic memories, lit up. Next, Graff used exposure-based therapies, similar to those used on humans, to reduce fear in the mice. Surprisingly, some of the neurons active when recalling traumatic memories were still active when the mice no longer showed fear, meaning that storing and forgetting memories are controlled by the same group of neurons. In this way, these neurons act like a light switch when remembering a traumatic experience, ultimately leading to attenuation of fear. The research completed by Vukojevik and Graff is incredibly promising and may lead to the development of specialized therapies in the future. However, the current most effective treatments for trauma continue to be cognitive behavioral therapy (CBT) and eye movement desensitization and reprocessing (EMDR). Both of these therapies aim to expose the patient to small parts of the traumatic event in short intervals through talking about the experience and allowing new memories and associations to be formed so that the trauma is not all-consuming. EMDR and CBT are widely used with PTSD patients, and with good reason, as the most effective way to overcome trauma is to speak about it with a trusted mental health professional. While it is tempting to block out traumatic memories forever, it is far more effective to seek help and therapy, even if it requires taking that extra step of courage to reach out. If you are a Northeastern student and just need to talk to someone, please use Find@Northeastern (1.877.233.9477) for 24/7 mental health support.

Science (2018). DOI: 10.1126/science.aas9875PNAS (2020).

DOI: 10.1073/pnas.2008415117