Trauma can lead to a range of debilitating physical and psychological health conditions. Most notably, trauma can result in post-traumatic stress disorder (PTSD). PTSD is characterised by intense flashbacks to the traumatic event(s), nightmares, hyperarousal, and disturbing emotions and memories.1 Survivors of PTSD have been known to engage in avoidant behaviours such as social withdrawal and substance abuse.2
This blog will explore the physical effects of trauma on the brain and how it impacts the realities and perceptions of trauma survivors.
A trigger is something that reminds us of our trauma.3 This can be a person, place, object, smell, sound, or memory. If you have PTSD and are triggered, the memory of the trauma returns, and you will likely experience physical and psychological discomfort. Triggers are challenging to deal with, and can cause to engage in unhealthy behaviours to cope.

Trauma and the Brain

Several areas of the brain are responsible for healthy functioning and development in individuals. This includes the hippocampus, the amygdala, and the prefrontal cortex. These areas of the brain are associated with learning, memory, stress, and overall emotional regulation. If these areas are negatively affected, as they often are in those experiencing PTSD and other trauma-related conditions, their ability to function in every-day life is compromised.
Trauma and its impact on brain health can have a knock-on effect. As this blog will explore later, trauma can lead to a reduction in volume and functional health of an area of the brain responsible for memory and learning, known as the hippocampus. When the hippocampus is damaged, we are less able to discern between past and present experiences. This has negative consequences. This inability to differentiate can make a person with PTSD believe that the traumatic event is happening all over again. This can cause the person to go to great lengths to escape their perceived situation.
Until it is resolved, trauma can disrupt several areas of a person’s life, including their professional or academic performance, relationships, economic and financial well-being, and physical and psychological health.

Trauma and The Hippocampus

The hippocampus is the area of the brain associated with memory and learning new information4. The neurological impact of trauma is most pronounced in the hippocampus. According to research published in the journal Biology Psychiatry, along with many other studies, subjects with PTSD showed a reduced hippocampal volume compared to participants who did not have PTSD.5 This may be in part due to an extended release of cortisol6, claims a report in Learning & Memory. When we experience trauma or re-experience trauma, high cortisol levels are released in the brain. Cortisol is a normal, naturally occurring brain chemical, but it becomes neurotoxic when it is released for an extended period7.
The hippocampus governs our memory. When healthy and functional, it helps us create new memories and recall old memories in response to relevant stimuli. It is also responsible for helping us to distinguish between memories and present experiences.
When the volume of our hippocampus decreases, as is seen in many PTSD survivors, the ability to discern between memories and present experiences is compromised.8 As a result, it is hard for a person with PTSD to interpret environmental situations in the correct context.
In environmental situations where even a slight reminder of one’s trauma is experienced, the PTSD survivor is likely to go through a heightened stress response. The brain responds to the trigger as though the traumatic event is happening again. A person who experienced a traumatic event in an underground parking lot may hold a deep fear of parking lots, even after the event. The place (the parking lot) triggers a threat response from the brain. Due to reduced hippocampal volume, the ability to differentiate the past and the present is reduced, and the person is likely to experience extreme stress and panic.

Trauma and the Ventromedial Prefrontal Cortex

The ventromedial prefrontal cortex (vmPFC) is an area of the brain responsible for regulating emotional responses that began in the amygdala9. More specifically, the vmPFC regulates our fear response. In those who have been impacted by trauma, there is often a noticeable decrease in the volume of the vmPFC and a reduction in its functional ability.
Reduced volume and functioning of the vmPFC means that the person with PTSD will tend to be fearful, stressed, and anxious in the face of triggers, or reminders, which are loosely connected to the original traumatic event(s).

Trauma and the Amygdala

The amygdala is the region of the brain that helps us process emotions and activate our fear response10. Over years of evolution, the amygdala has learned to act fast in the face of threat. Even a second can make a difference when faced with real danger.
According to research in Dialogues in Clinical Neuroscience, trauma increases the level of activity in the amygdala.11 Trauma survivors, particularly those who now have PTSD, often exhibit hyperactivity in this region of the brain when they meet a trigger.


The amygdala, the vmPFC, and the hippocampus all play a role in how our brains process and tolerate stress.12 The hippocampus elicits appropriate responses to stimuli, preventing the amygdala from unnecessarily entering survival mode. The vmPFC regulates our emotional responses by governing the function of the amygdala. Then, it makes sense that when the hippocampus and the vmPFC are negatively affected by trauma, the amygdala goes into overdrive.

Trauma, the Brain, and Psychological Health

Research published in Dialogues in Clinical Neuroscience suggests that those who have PTSD are at risk of developing other psychotic and mood disorders.13 It is believed that the risk of developing other conditions relates to the changes in brain chemistry caused by the trauma. It is crucial to consider the impact of PTSD on brain functioning and chemistry, because such an understanding offers insight into effective and appropriate treatment options. With the right clinical diagnosis, it is possible to treat PTSD.

1 Bisson, Jonathan I et al. “Post-Traumatic Stress Disorder”. BMJ, 2015. BMJ, doi:10.1136/bmj.h6161. Accessed 30 Dec 2020.
2 Charuvastra, Anthony, and Marylene Cloitre. “Social bonds and posttraumatic stress disorder.” Annual review of psychology vol. 59 (2008): 301-28. doi:10.1146/annurev.psych.58.110405.085650
3 Center for Substance Abuse Treatment (US). Trauma-Informed Care in Behavioral Health Services. Rockville (MD): Substance Abuse and Mental Health Services Administration (US); 2014. (Treatment Improvement Protocol (TIP) Series, No. 57.) Chapter 3, Understanding the Impact of Trauma. Available from:
4 Anand, Kuljeet Singh, and Vikas Dhikav. “Hippocampus in health and disease: An overview.” Annals of Indian Academy of Neurology vol. 15,4 (2012): 239-46. doi:10.4103/0972-2327.104323
5 Logue, Mark W et al. “Smaller Hippocampal Volume in Posttraumatic Stress Disorder: A Multisite ENIGMA-PGC Study: Subcortical Volumetry Results From Posttraumatic Stress Disorder Consortia.” Biological psychiatry vol. 83,3 (2018): 244-253. doi:10.1016/j.biopsych.2017.09.006
6 Kim, Eun Joo et al. “Stress effects on the hippocampus: a critical review.” Learning & memory (Cold Spring Harbor, N.Y.) vol. 22,9 411-6. 18 Aug. 2015, doi:10.1101/lm.037291.114
7 Qin, Dong-Dong et al. “Prolonged secretion of cortisol as a possible mechanism underlying stress and depressive behaviour.” Scientific reports vol. 6 30187. 22 Jul. 2016, doi:10.1038/srep30187
8 Malivoire, B.L., Girard, T.A., Patel, R. et al. Functional connectivity of hippocampal subregions in PTSD: relations with symptoms. BMC Psychiatry 18, 129 (2018).
9 Hiser, Jaryd, and Michael Koenigs. “The Multifaceted Role of the Ventromedial Prefrontal Cortex in Emotion, Decision Making, Social Cognition, and Psychopathology.” Biological psychiatry vol. 83,8 (2018): 638-647. doi:10.1016/j.biopsych.2017.10.030
10 Ressler, Kerry J. “Amygdala activity, fear, and anxiety: modulation by stress.” Biological psychiatry vol. 67,12 (2010): 1117-9. doi:10.1016/j.biopsych.2010.04.027
11 Bremner, J Douglas. “Traumatic stress: effects on the brain.” Dialogues in clinical neuroscience vol. 8,4 (2006): 445-61. doi:10.31887/DCNS.2006.8.4/jbremner
12 McEwen, Bruce S, and Peter J Gianaros. “Central role of the brain in stress and adaptation: links to socioeconomic status, health, and disease.” Annals of the New York Academy of Sciences vol. 1186 (2010): 190-222. doi:10.1111/j.1749-6632.2009.05331.x
13 Flory, Janine D, and Rachel Yehuda. “Comorbidity between post-traumatic stress disorder and major depressive disorder: alternative explanations and treatment considerations.” Dialogues in clinical neuroscience vol. 17,2 (2015): 141-50. doi:10.31887/DCNS.2015.17.2/jflory

We are here to help

Share on facebook
Share on twitter
Share on linkedin

More articles from Addcounsel

Alcohol Rehab

Suicide and Bipolar – How to manage the risks

Suicide is the most prevalent cause of death worldwide. It is on the extreme point of the suicidal spectrum of suicidal thoughts and behaviours. This spectrum ranges from risk-taking personality to different degrees of suicidal acts and even complete suicide. It has been long debated upon that suicide is a sudden act of vulnerability, but on a deeper level of analysis, it is long-considered ideation based upon hopelessness and collective unfortunate circumstances

Read More »
Alcohol Rehab

Addcounsel, where the wealthy come to be treated for mental health in London

Mental health illnesses have been a major cause behind preventable deaths and disease burden in the world. Specifically in the United Kingdom, 16% of the population goes through mental illnesses such as major depressive disorder, suicidal behaviours, alcohol and drug abuse and anxiety. There is a growing number of people who have mixed anxiety and depression, coming around 7% in the young population.

Read More »
Alcohol Rehab

Treating addiction in the older population

Alcohol use disorder is said to be lessened in the later age population but there is a growing statistic for older adults. As we grow old, many stressful life events can make us vulnerable, such as the death of a loved one, divorce or separation, lack of physical mobility, lifestyle illnesses and retirement liabilities.

Read More »