Post-traumatic stress disorder (PTSD) is a mental health condition originating from a past traumatic event. Reactions that occur during and after trauma are typical, but when symptoms continue well after the event has passed, it may signify a person has PTSD.

The brain works in complex ways to keep a person safe. Experiencing trauma can alter the structure and functions of the brain, even long after the traumatic event has occurred. Continuing to experience debilitating fear, flashbacks, or extreme stress without any actual danger is post-traumatic stress.

PTSD affects the brain by taking memories of past traumatic experiences and applying them to current or future situations that pose no actual threat. It is a form of injury to the brain that requires treatment.

This article explains how PTSD affects and alters the brain. It also explores the treatments available and how to navigate recovery to lead a fulfilling life.

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PTSD is essentially the brain’s “alarm system” becoming overly sensitive from experiencing a past traumatic event. Anything that loosely reminds the brain of the specific trauma can become triggering, resulting in symptoms that seem as though the trauma is occurring again.

It is important to know how the brain works to understand how PTSD affects it. The National Institute of Neurological Disorders and Stroke (NINDS) describes the brain in three parts: the forebrain, midbrain, and hindbrain.

  • The forebrain: This is the largest part of the brain, containing the cerebrum. It controls a person’s actions, holds memories, and allows people to plan, imagine, think, recognize friends, play games, and read.
  • The midbrain: This controls functions such as eye movement and reflexes.
  • The hindbrain: The hindbrain contains the cerebellum and the spinal cord. It controls learned movements, respiration, and heart rate.

Certain structures sit within these three parts of the brain, including:

  • The amygdala: The amygdala, meaning “almond,” is a small almond-shaped area in the brain responsible for emotional processing, particularly anxiety and fear. It also links emotions to other brain abilities, such as memories and learning.
  • The hippocampus: The hippocampus is responsible for memory, learning, feeling, and reacting and is part of the overall limbic system. It works with the amygdala to control the flight, fight, or freeze mode, which involves symptoms such as rapid breathing and muscle tensing.
  • The prefrontal cortex: The prefrontal cortex controls executive functions such as planning, making decisions, self-control, and problem-solving.
  • The nervous system: The nervous system includes the spinal cord and brain, and carries messages from the brain to different parts of the body. It uses neurons to create a communication network that involves moving, breathing, seeing, and thinking.
  • The anterior cingulate cortex (ACC): The ACC is responsible for cognitive processes such as decision making, motivation, learning, conflict and error monitoring, and cost-benefit calculation.

These structures affect how the brain processes events, including traumatic events. As a traumatic event plays out, the brain shuts off certain mind and body processes to help manage it. The sympathetic nervous system increases the amount of stress hormones, putting the body into flight, fight, or freeze mode.

The sympathetic nervous system should calm down once the threat ends and the brain resumes standard functioning. However, if the flight, fight, or freeze mode does not switch off, the brain cannot resume its usual functions and remains in a permanent state of survival mode.

Andy’s story: How PTSD affects the brain

“PTSD is a gradual onset condition that you don’t know you have until it manifests itself. I started to shut down in certain areas of contact with other people and shied away from interaction in social settings. I still do not like going to movie theaters because I feel claustrophobic if I cannot identify all the exits. I have never felt that I was in any way cognitively impaired, but I began to become hypersensitive and alert to my surroundings.

PTSD is incredibly personal to each individual affected by it. PTSD made me angry at times for no specific reason. I would snap at my spouse and children. My wife told me that I would whimper in my sleep. PTSD memories are something that you try to avoid at all times, but ghosts of the past can arise at any time for almost any reason. You try to bury the past so that it will not hurt you anymore, but the memories come back when you least expect them.

I experienced all manner of symptoms, such as poor sleep, jumpiness, avoidance of loud noises, and lack of desire to interact in large social gatherings. I used alcohol to self-medicate and was always hyper-alert to my surroundings to the point of distraction.

I luckily began having treatments, however, including three months of cognitive therapy, physical training, dietary counseling, and hyperbaric oxygen therapy treatments. I now sleep a solid night with no more troubling dreams or crying out. I interact better with others, and my anger has subsided.”

Learn more about PTSD.

The amygdala influences how a person remembers their fears or a traumatic event. During a traumatic event, adrenaline and stress hormones flood the body, and this memory imprints onto the amygdala. The amygdala holds memories of events through the five senses: taste, touch, hearing, smell, and sight.

The traumatic event keeps looping like a video with the emotional side of the brain while also disconnecting from the side that involves reasoning and cognitive processing. Similar to a fire alarm, the amygdala goes off when it senses danger. However, those with PTSD have a hyperactive amygdala that does not turn off.

Studies show hyperactivity in the amygdala in patients with PTSD, as it fails to recognize the threat is no longer there. The amygdala responds as though the person is still experiencing the event for the first time when specific sensory-related triggers occur. For example, a person who has experienced a car crash may have symptoms such as hypervigilance, high levels of stress, and intense fear when hearing the sounds of cars.

Research also shows that PTSD causes structural changes in the amygdala, resulting in it reading ordinary situations or events as dangerous and threatening. This can cause disruption and problems in a person’s day-to-day life.

The hippocampus is where short-term memories reside. When a traumatic event occurs, the hippocampus works hard to remember the memory accurately and make sense of what happened. However, traumatic events can be overwhelming for the brain to process, meaning it may record things inaccurately. This can result in numerous PTSD symptoms, such as:

  • being unable to remember accurate details of what happened
  • ruminating on the event as the brain tries to make sense of what happened
  • feeling like the brain is always on the lookout for future threats
  • being in a constant state of hypervigilance since it is hard to distinguish between past and current events

The amygdala and hippocampus work together to relay messages about the body back and forth. PTSD UK uses the example of a person being surprised by fireworks: in a split second, the hippocampus relays information about fireworks to the amygdala, communicating that there is no danger and it is simply fireworks.

However, with trauma, the message relays inaccurately, linking to a traumatic event instead that contains similar aspects to experiencing fireworks, such as loud bangs. There is no message to calm the amygdala. Instead, emotions arising from the traumatic event resurface, including anxiety, fear, and flashbacks.

The hippocampus is reportedly smaller in patients with PTSD, leading to overall cognitive dysfunction.

The prefrontal cortex, also known as the “personality center,” is responsible for executive functions such as:

  • making decisions
  • processing memories
  • focusing on what one pays attention to
  • responding to a person’s surroundings

With PTSD, the prefrontal cortex has much lower activity than usual. The hippocampus and prefrontal cortex work together to respond appropriately and signal to the amygdala, or alarm system, that the threat is over. During this response, the physical symptoms of stress should cease.

However, low prefrontal cortex activity can result in a person becoming withdrawn, avoidant, or appearing irritable after a traumatic event. PTSD UK describes it as a defense mechanism where the brain uses emotional numbness to avoid reliving the pain of the trauma.

PTSD can also affect other functions of the frontal lobe, including:

  • issues with language, so a person may become unable to articulate their thoughts and emotions
  • storing memories incorrectly
  • making fear the dominant emotion

PTSD can cause the nervous system to be in constant overdrive. Emotions can feel overwhelming all the time, meaning a person may tolerate a lot less than before. This can result in situations that usually cause typical emotions to affect a person more deeply, and their reaction may not seem proportional to the situation.

When the brain’s alarm system constantly goes off, cortisol rushes through the body. Cortisol is a stress hormone that triggers the body into fight or flight mode. However, high levels of cortisol in the body without any actual danger can result in physical and emotional issues, such as:

Signs of the effects of PTSD on the brain include:

  • intrusive thoughts, particularly regarding the traumatic event
  • vivid and upsetting flashbacks
  • dreams of the event or distressing nightmares
  • insomnia
  • avoidance of anything that is a reminder of the traumatic event, including places, people, or situations
  • problems with memory
  • distorted thoughts about the event or oneself, such as perceiving oneself to be a bad person
  • depression relating to ongoing sadness or fear
  • feeling distraught
  • issues with mood, such as outbursts, irritability, or being self-destructive
  • physical sensations such as feeling sick, headaches, or chest pain

These signs of PTSD can affect a person’s daily life. It can be difficult to function if someone is always on high alert and feels danger is imminent. It is important to look out for signs of PTSD so a person can get help from a healthcare professional.

Anna Goodman Herrick’s story, author of “A Speaker is a Wilderness: Poems on the Sacred Path from Broken to Whole:” How PTSD affects the brain

“Prior to treatment, I had difficulty concentrating on anything in the present, to the point that it was completely debilitating. I constantly experienced overwhelming emotions, including extreme depression, fear, and hypervigilance.

I initially had memories of the series of inciting traumatic incidents on repeat and had trouble focusing or doing anything else. I also avoided anything that reminded me of the event, and these reminders were everywhere. Intrusive memories made it especially challenging to focus or complete everyday tasks.

Finding a therapist who specialized in C-PTSD and inter-partner violence made a big difference in treatment, and she included narrative exposure, which helped. Trauma-informed mindfulness made a big difference. Medication also helped. Because I’m a writer, I was fortunate to know that writing about it, such as journaling and poetry, could actually make a big difference in rewiring and helping to heal my brain, and it did.”

The brain is a resilient organ, and a person can reverse damage from trauma. With treatment and support, PTSD symptoms can subside, and each part of the brain can resume its typical function.

Treatment for PTSD includes:

Support for PTSD can help people by giving them a space to talk about the emotional, financial, and mental effects of the condition.

Options may include support groups, financial aid, and therapy. The following organizations may offer in-person or online support:

PTSD can have a major effect on the brain. A person may feel they are constantly on edge or repeatedly experiencing the traumatic event. It is important to recognize the signs of PTSD so a person can get professional help as soon as possible.

Treatment to help a person recover from PTSD may include medications such as antidepressants, therapy, and engaging with support groups.