When we go through trauma, our brains don’t function like they normally do. We shift into survival mode. Like a deer in the headlights, our brains direct all our mental and physical energy toward dealing with the immediate threat until it’s gone. In normal situations, this state fades over time. Trauma isn't just something we experience after being in a warzone or in a violent situation, we can be traumatized by our relationships.
Sometimes, though, our initial trauma response sticks, making it difficult for us to function as we’d like. Trauma can change the way we think, feel, and act for a long time after the initial event. For many people, this could mean flashbacks or nightmares, a constant feeling of being on edge, loneliness, anger, intrusive thoughts and memories, self-destructive actions, and more.
All these things are very normal responses to trauma, but they don’t always go away on their own. The good news is that patterns that might seem permanent can actually be reversed--with the right approach and knowledge, you can shift your brain towards healing. However, it can be difficult to see a path forward without first understanding how and why these changes happen.
Trauma can change your brain on many levels, from the way you make decisions down to your immediate, subconscious responses to the world around you. Part of the reason it can be so hard to overcome the effects of trauma is that it goes after several areas of your brain at once.
According to a 2006 study by NIH, trauma mainly affects three important parts of your brain: the amygdala, which is your emotional and instinctual center; the hippocampus, which controls memory; and the prefrontal cortex, which is responsible for regulating your emotions and impulses. All three parts work together to manage stress.
When you’re reminded of a traumatic experience, your amygdala (emotional and survival center) goes into overdrive, acting just as it would if you were experiencing that trauma for the first time. Your prefrontal cortex also becomes suppressed, so you’re less capable of controlling your fear--you’re stuck in a purely reactive state.
Meanwhile, trauma also leads to reduced activity in the hippocampus, one of whose functions is to distinguish between past and present. In other words, your brain can’t tell the difference between the actual traumatic event and the memory of it. It perceives things that trigger memories of traumatic events as threats themselves.
Trauma can cause your brain to remain in a state of hypervigilance, suppressing your memory and impulse control and trapping you in a constant state of strong emotional reactivity.