Effects of Trauma on the Nervous System

Important information to remember.

Parasympathetic Nervous System: The parasympathetic nervous system (PSNS) or rest-and-digest system, is part of the autonomic nervous system, along with the sympathetic nervous system. Located between the brain and spinal cord, the PSNS is tasked with saving the body’s energy by slowing the heart rate and increasing the activity of the intestines and glands during periods of rest. It also relaxes the sphincter muscles in the gastrointestinal system.

Sympathetic Nervous System: The sympathetic nervous system or fight-flight mode is responsible for rapid activation of the body’s emergency survival response in the face of actual or perceived threat, emotional or physiological overwhelm, or traumatic memories, reminders and conditioned reactions.

Explicit Memory: Explicit memory refers to the conscious retrieval of past information or experiences. This is when the individual is in a situation that triggers them to remember a direct previous experience.

Implicit Memory: Implicit memory refers to an unintentional or unconscious form of retrieval. This is when the individual is in a situation that triggers them to react unintentionally to the situation without making any direct connection to a previous experience.

False Memory: False memory refers to when the nervous system distorts the actual memory to create a half true scenario to help the individual bypass the actual traumatic experiences.

Traumatic experiences can dysregulate the nervous system. In periods of stress, the body’s sympathetic nervous system (fight or flight) activates. A normally regulated nervous system experiences the stress but returns to normal when the threat has passed. This period during which you have the ability to self regulate is called the window of tolerance, and most people move through several of these cycles daily. However, the system works differently when the body experiences trauma.

Traumatic events push the nervous system outside its ability to regulate itself. For some, once their sympathetic nervous system gets activated, it never deactivates, causing the person to overstimulate and unable to calm down resulting in anxiety, anger, restlessness, panic, and hyperactivity. This physical state of hyperarousal is stressful for every system in the body. In other people, once the dorsal shut down (freeze or fold) mode of the parasympathetic nervous system gets activated it never deactivates, resulting in depression, disconnection, fatigue, and lethargy. People can alternate between these highs and lows.

In cases of extreme and chronic trauma the nervous system becomes conditioned to exist in a state of fear where the individual develops unhealthy coping mechanisms resulting in serious emotional, physical, and behavioral health problems. That state can continue into adulthood, triggered by things that would seem utterly unrelated to childhood trauma.