The Effects Trauma has on the Brain
Trauma can have many harsh effects on the brain and can change the course of someone’s life. When someone experiences trauma, brain chemistry is altered, and the brain begins to function differently. The amygdala, hippocampus, and prefrontal cortex can all potentially be affected by the trauma someone with a developing brain may experience. Studies have shown that people with post-traumatic stress disorder (PTSD) may have smaller hippocampal and anterior cingulate volumes and increased amygdala function. People with PTSD may also experience having increased cortisol and norepinephrine responses to stress.
After experiencing trauma, one’s brain will go through biological changes that it normally wouldn’t have. The parts of the brain that are affected the most by trauma are having an overstimulated amygdala, underactive hippocampus, and ineffective variability. With the hippocampus and trauma, the stress hormone glucocorticoid increases and kills cells in the hippocampus. These cells are important because without them, it’s harder to make the synaptic connections necessary for memory consolidation. With ineffective variability, the constant elevation of stress hormones interferes with the body’s ability to regulate itself.
The amygdala, which is near the hippocampus, in the prefrontal part of your brain, controls emotions and tagging memory with emotions. The amygdala is often known for being the part of your brain that goes into “fight or flight” during a threatening situation. Walter Bradford Cannon first described the theory that animals react to a general discharge of the sympathetic nervous system, preparing the animal for fighting or fleeing. Estrogen, testosterone, and cortisol, as well as the neurotransmitters dopamine and serotonin, affect how humans react to stress. The release of chemical messengers results in the production of the hormone cortisol, which increases blood pressure. Catecholamine hormones, such as adrenaline, or noradrenaline, facilitate immediate reactions associated with a preparation for violent muscular actions. The reaction you take during a fight, flight, or freeze scenario will also be determined by the nature and intensity of the behavioral response. When freezing, progesterone and estrogen also play a role. When someone is experiencing extreme fear, their “fear circuitry” may kick in, which results in their prefrontal cortex functioning less effectively or even shutting down. When the amygdala shuts down, your brain becomes disorganized and overwhelmed because of the trauma. This causes the brain to go into survival mode, which shuts down the higher reasoning and consciousness.
After trauma, the amygdala can become highly alert and in an activated loop during which it looks for and perceives threats everywhere. 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. Hypervigilant individuals are also in a state of extreme alertness that undermines the meaning of life. They may be more aware due to the trauma they experienced, which caused them to question their safety at all times. Hypervigilance can leave one feeling exhausted and may even interfere with someone’s ability to function on a day-to-day basis.
Some people may think that the effects of trauma are irreversible, except that is wrong because our brains are very adaptable. Neuroplasticity, or the brain’s ability to form new connections, is proof that we can rewire our brains to reverse the damaging effects trauma can have on someone.