Post-traumatic stress disorder (PTSD) is a mental health condition that happens after a person has experienced a traumatic event. PTSD affects everyone differently. For some, it affects the core of their daily lives. For others, PTSD is triggered by events that are similar to the source of their trauma.
The brain and body change after a traumatic incident, whether that trauma be from assault, combat, or witnessing something horrific. After traumatic events, roughly 20% of adult survivors develop symptoms of PTSD. For those who live with PTSD, the effect of the disorder can be deeply troubling and difficult to cope with.
What is happening to the brain that initially causes PTSD?
To understand this, we need to first understand how the brain ideally functions in response to stress. Essentially, there are three sections of your brain:
- Reptilian: This is your base brain level, responsible for survival instincts and unconscious body functions like breathing. This is governed by your brainstem.
- Mammalian: This is the second-tier part of your brain that processes emotion and sensation. This is controlled by your limbic system and your midbrain.
- Neomammalian: The most advanced part of your brain, this governs cognitive thinking, decision making, learning, and memory. This is controlled by your cerebral cortex and forebrain.
In a traumatic situation, your reptilian brain takes over and shifts the body into survival mode. The nervous system creates stress hormones, such as adrenaline and cortisol. These stress hormones create a heightened awareness and prepare the body to fight, flee or freeze. This is the evolutionary response that developed to help humans escape or survive life-threatening situations.
In an ideal situation, once the immediate threat or traumatic occurrence stops, your nervous system signals to your brain that it can continue as usual. It’s kind of like rebooting a computer: your reptilian brain crawls back into your base brain and rests while your mammalian and neomammalian brain begin processing again.
In some situations, the nervous system fails to deliver the memo to the reptilian brain. Instead of staying buried until a life-threatening situation occurs, the processes that kick on when you enter survival mode stick around and simmer underneath the surface. This holds the survivor in a constant reactive state. This is what we call PTSD.
The daily processes of a brain with PTSD
People with PTSD often experience four major symptoms: intrusive thoughts, mood alterations, hypervigilance, and avoidance of all trauma-related things. These symptoms can be incredibly distressing to survivors, who suddenly find themselves out of control of their own minds and bodies.
Symptoms of PTSD are caused by 3 major brain functions:
- Overactive amygdala: The amygdala is responsible for identifying survival threats and for tagging memories with emotions. After trauma, the amygdala stays on red-alert and remains hyper-vigilant, causing you to perceive threats everywhere.
- Under-stimulated hippocampus: The hippocampus is responsible for memory consolidation and processing. Prolonged and constant stress hormones damage the hippocampus, making it less effective at processing and categorizing memories. This means that the brain does not categorize the traumatic event as past-tense and still responds as though the event hasn’t stopped.
- Ineffective chemical regulation: Constant stress hormones interrupt your body’s ability to regulate its own chemistry. Brain chemicals like serotonin and dopamine, which boost mood and calm anxiety, don’t make it to your nervous system properly. This leads to unregulated feelings of depression, anxiety and fatigue.
People with Post-Traumatic Stress Disorder experience long-term emotional and physical hardship because of a traumatic incident. These hardships are rooted in actual biological changes in the wake of trauma. It’s important to remember that, for those with PTSD, the traumatic incident isn’t over yet.
