How Does Trauma Affect the Brain?

Trauma can leave lasting effects on the body and mind, but have you ever wondered — how does trauma affect the brain? When someone goes through a deeply distressing event, it can actually change how their brain works. These changes can affect their memory, emotions, and even decision-making.

However, while these changes may feel permanent, they are not. With the right strategies and understanding, healing is possible. The first step toward recovery is gaining awareness.

How the Brain Responds to Trauma

To understand how trauma affects the brain, it helps to know that the brain develops and changes throughout a person’s life. Important growth happens during childhood, adolescence, and adulthood.

At each stage, the brain goes through different changes, which can make it more sensitive to the effects of trauma at certain times.

For example, the amygdala, hippocampus, and prefrontal cortex — parts of the brain that control emotions, memory, and decision-making — react to trauma in different ways depending on a person’s stage of development [*].

Below, we’ll explore how trauma influences these areas:

Amygdala becomes overstimulated

The amygdala, a small, almond-shaped structure located deep in the brain, acts like the brain’s alarm system. It helps you react to danger by triggering your “fight, flight, or freeze” response [*].

For example, if a dog suddenly barks loudly at you, your amygdala makes your heart race and prepares your body to protect itself. This is a normal and helpful reaction to keep you safe.

However, when someone experiences trauma, the amygdala can become overstimulated, like an alarm that goes off too often, even when there’s no real danger. This can make a person feel constantly on edge, anxious, or easily startled — despite being in safe situations.

It’s as if the brain gets stuck in “alert mode.”

Reduced activity in the hippocampus

The hippocampus is a small, curved structure in the brain located near the amygdala. It acts like your brain’s filing system, which helps you store and organize memories.

For example, if you go on a fun vacation, your hippocampus helps you remember the details, like where you went and what you enjoyed, so you can think back on it later.

Experiencing trauma can cause the hippocampus to become less active. This makes it difficult to distinguish between the past and the present and can lead to a feeling of reliving frightening experiences. It’s as though the brain has trouble organizing those memories.

Many studies show that adults who went through childhood trauma, like abuse or neglect, usually have a smaller hippocampus. Over time, stress may change the hippocampus’s structure, especially if the trauma happens early in life [*].

The prefrontal cortex becomes suppressed

The prefrontal cortex (PFC) is the part of the brain right behind your forehead. It helps with thinking, decision-making, and controlling emotions.

For example, if you feel angry but take a deep breath and calm down instead of yelling — your prefrontal cortex is helping you stay in control.

Trauma can weaken the prefrontal cortex, and this can make it harder for a person to stay calm, think things through, or control their reactions. When the prefrontal cortex is not working as well, emotions can take over more easily.

Brain scans in humans show that people who have experienced a lot of stress tend to have a smaller PFC and weaker connections between the PFC and the amygdala. This means their ability to manage emotions and stress is reduced, which would leave them stuck in a more reactive state [*].

Symptoms of Trauma-Induced Brain Changes

As trauma affects the brain, it can lead to noticeable changes in thoughts, emotions, and behavior. These changes are linked to how the brain areas we discussed respond to stress.

One common symptom is heightened fear and anxiety. The amygdala becomes overactive, which makes a person feel constantly on edge.

Trauma can also cause difficulty distinguishing the past from the present. When the hippocampus, the brain’s memory center, becomes less active, it struggles to process memories properly. Flashbacks or a sense of reliving traumatic events can happen.

Another effect is trouble controlling emotions. A weakened prefrontal cortex makes it harder to regulate emotions. This may result in sudden mood swings, irritability, or feeling easily overwhelmed.

This imbalance between emotional and logical thinking may also lead to impulsive or risky behavior since the brain has difficulty weighing consequences before acting.
Sleep issues are also common, given that trauma can lead to hypervigilance and disrupted sleep patterns.

Finally, trauma can affect relationships, which leads to social withdrawal and difficulty trusting others. This is because dysregulation can make it challenging to connect with people. Some tend to isolate themselves or avoid social situations altogether.

Can the Brain Reverse Trauma’s Damaging Effect?

Yes, the brain can heal after trauma. The brain is always changing and adapting, which means it can form new connections and recover from stress. This ability is called neuroplasticity — it’s what helps us learn new things, build new habits, and even heal from difficult experiences.

Even though trauma can affect how the brain works, support from others (loving relationships and professional help) and healthy coping strategies can improve a person’s ability to handle emotions and stress.

Think of healing from trauma like strengthening a muscle — the more you practice healthy thoughts and behaviors, the stronger and more resilient your brain becomes.

There are many ways to support the brain’s healing after trauma. Therapy approaches like play therapy and trauma-focused cognitive behavioral therapy (TF-CBT) are especially effective for children.

Therapies like cognitive-behavioral therapy (CBT) and dialectical behavior therapy (DBT) benefit teens and adults, as they teach valuable skills to manage strong emotions, cope with distress, and improve relationships. Eye movement desensitization and reprocessing (EMDR) is another effective approach that helps both teens and adults reprocess traumatic memories.

Beyond formal therapy, individual strategies like mindfulness, breathing exercises, and journaling can also support healing.

The Bottom Line

Knowing the connection between trauma and the brain helps us see that healing is not only possible but also backed by science. Trauma can change how the brain processes emotions, memories, and stress — but the brain’s ability to adapt means recovery is within reach.

Whether through therapy, healthy coping strategies, or strong relationships — children, teens, and adults can retrain their brains to respond to life in healthier ways.

If you’re looking for tools to support healing, explore our Trauma Worksheets category. These worksheets can be used in therapy sessions or at home to help children and teens process their experiences and learn coping skills!

References:

1. Bremner, J. D. (2006). Traumatic stress: Effects on the brain. Dialogues in Clinical Neuroscience, 8(4), 445. https://doi.org/10.31887/DCNS.2006.8.4/jbremner
2. Professional, C. C. M. (2024a, May 1). Amygdala. Cleveland Clinic. https://my.clevelandclinic.org/health/body/24894-amygdala
3. Carrión, V. G., Haas, B. W., Garrett, A., Song, S., & Reiss, A. L. (2009). Reduced Hippocampal Activity in Youth with Posttraumatic Stress Symptoms: An fMRI Study. Journal of Pediatric Psychology, 35(5), 559. https://doi.org/10.1093/jpepsy/jsp112

4. Arnsten, A. F., Raskind, M. A., Taylor, F. B., & Connor, D. F. (2014). The effects of stress exposure on prefrontal cortex: Translating basic research into successful treatments for post-traumatic stress disorder. Neurobiology of Stress, 1, 89-99. https://doi.org/10.1016/j.ynstr.2014.10.002