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The Neurological Basis of PTSD

Post-Traumatic Stress Disorder (PTSD) is a mental health condition that can develop after someone experiences or witnesses a very stressful, frightening, or life-threatening event. This can happen after accidents, abuse, natural disasters, or war. For those with PTSD, memories of the event do not fade. It feels like the brain keeps returning to that moment, as if the danger never ended.

PTSD can affect people in various ways. Some main symptoms include:

  • Intrusion: People might have unwanted memories, nightmares, or flashbacks where they feel like the event is happening again.

  • Avoidance: They may try to stay away from people, places, or situations that remind them of what happened.

  • Negative thoughts and mood: PTSD can make someone feel numb, sad, or detached. They may lose interest in activities they once enjoyed or feel disconnected from others.

  • Changes in arousal and behavior: Many people with PTSD feel tense or on edge. They might get angry easily, act recklessly, or struggle with sleep or focus.

  • Derealization and depersonalization: Some people describe a feeling like the world isn’t real, or like they are watching themselves from outside their body.

To be diagnosed with PTSD, symptoms must last longer than a month and disrupt the person's ability to live normally. PTSD can start soon after the trauma, but sometimes it appears months or even years later. It can also occur alongside depression, anxiety, substance use, or memory problems.


What Happens in the Brain?

Researchers have found that PTSD changes how certain parts of the brain work, particularly the amygdala, hippocampus, and prefrontal cortex. These areas control fear, memory, and emotions.


The amygdala senses danger. In people with PTSD, it becomes overactive, leading to constant fear and anxiety, even when the person is safe.


The hippocampus helps us store memories and distinguish between past and present. This area is often smaller in people with PTSD, which may explain why flashbacks feel so real—the brain struggles to recognize that the event is over.


The prefrontal cortex controls emotions and decision-making. In PTSD, it often becomes less active, making it unable to calm the amygdala. This makes it harder for people to manage their fear and stress.


These changes are also influenced by stress hormones like cortisol and norepinephrine, which are released when someone is in danger. In PTSD, the brain’s response to these hormones becomes unbalanced, keeping the body stuck in “fight or flight” mode.


Even though trauma changes the brain, it can still heal. The brain is plastic, meaning it can form new connections and recover over time. Treatments like cognitive-behavioral therapy (CBT), eye movement desensitization and reprocessing (EMDR), and mindfulness-based therapy help people process memories and regain control over their emotions. Brain scans have shown that after successful therapy, the amygdala becomes less active, and the prefrontal cortex becomes stronger, allowing the person to feel calmer and safer.


PTSD is not just a brain issue; it also affects how a person feels about themselves and the world. Imagine feeling unsafe in your own mind, as if your body is still stuck in a moment you want to forget. Many people with PTSD face this struggle every day. Understanding the brain helps us see that PTSD is not a sign of weakness. It’s a normal response to something overwhelming. The brain learns to protect itself, even if it leads to pain later. Knowing this can help us offer more empathy and support to those affected by trauma.


In conclusion PTSD is both a psychological and neurological disorder. It impacts how the brain handles memory, fear, and emotion. The overactive amygdala, smaller hippocampus, and weaker prefrontal cortex all contribute to PTSD symptoms. The good news is that the brain can heal with therapy, care, and time. Trauma may change how the brain functions, but it does not destroy the person. People with PTSD can still rebuild their sense of safety and hope. Understanding both the science and the human aspect of PTSD reminds us that recovery is always possible.



References

  1. J. Douglas Bremner, Bernet Elzinga, Christian Schmahl, Eric Vermetten, Structural and functional plasticity of the human brain in posttraumatic stress disorder, Editor(s): E. Ronald De Kloet, Melly S. Oitzl, Eric Vermetten, Progress in Brain Research, Elsevier, Volume 167, 2007, Pages 171-186, ISSN 0079-6123, ISBN 9780444531407, https://doi.org/10.1016/S0079-6123(07)67012-5. (https://www.sciencedirect.com/science/article/pii/S0079612307670125)

  2. Bremner JD. Traumatic stress: effects on the brain. Dialogues Clin Neurosci. 2006;8(4):445-61. doi: 10.31887/DCNS.2006.8.4/jbremner. PMID: 17290802; PMCID: PMC3181836. Donald Egan, M.D. March 2025

  3.   American Psychiatric Association. (2022). Trauma- and Stressor-Related Disorders. In Diagnostic and Statistical Manual of Mental Disorders (5th ed., text rev.).

  4. Bichitra Nanda Patra and Siddharth Sarkar. Adjustment Disorder: Current Diagnostic Status. Indian J Psychol Med. 2013 Jan-Mar; 35(1): 4–9.

  5. Harvard Medical School. (2007). National Comorbidity Survey (NCS). (2017, August 21). Data Table 2: 12-month prevalence DSM-IV/WMH-CIDI disorders by sex and cohort.

  6. National Library of Medicine: MedlinePlus. Adjustment Disorder.

  7. American Academy of Child and Adolescent Psychiatry. Facts for Families: Attachment Disorders.

  8. Merikangas KR, He JP, Burstein M, et al. Lifetime prevalence of mental disorders in U.S. adolescents: results from the National Comorbidity Survey Replication–Adolescent Supplement (NCS-A). J Am Acad Child Adolesc Psychiatry. 2010 Oct;49(10):980-9.>

  9. Substance Abuse and Mental Health Services Administration. SAMHSA’s Concept of Trauma and Guidance for a Trauma-Informed Approach. HHS Publication No. (SMA) 14-4884. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2014.

  10. Brewin, C.R. (2019). Complex post-traumatic stress disorder: a new diagnosis in ICD-11. BJPsych Advances, 26, 145 - 152.

  11. Schnurr, P. P., et al (2022). Comparison of Prolonged Exposure vs Cognitive Processing Therapy for Treatment of Posttraumatic Stress Disorder Among US Veterans: A Randomized Clinical Trial. JAMA network open, 5(1), e2136921. https://doi.org/10.1001/jamanetworkopen.2021.36921

  12. Stein, D. J., Ipser, J. C., & Seedat, S. (2006). Pharmacotherapy for posttraumatic stress disorder (PTSD). The Cochrane database of systematic reviews, 2006(1), CD002795. https://doi.org/10.1002/14651858.CD002795.pub

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