Psychobiology of Trauma

By  Emily Spence Diehl, MSW

 Associate Director, Victim Advocacy Center

 Florida International University

(Originally published in the Florida Council of Sexual Abuse Services newsletter)

In 1889, researcher Pierre Janet philosophized that traumatic memories are stored differently in the brain than other types of experiences. He believed that traumatic memories are stored more as emotions and senses than as cognitions. Unfortunately, medical technology in the late 1800's was not as advanced as Janet's thoughts and beliefs. Since the early 1990's, an incredible amount of fascinating psychobiological research has begun to shed light on the physiological experience of trauma. If Pierre Janet were alive today, it is certain he would rejoice in the medical "proof" now available to support his theories.

To fully understand the physiological impact of trauma, it is important to review the body's emergency chemical responses and memory functions.

Emergency Response: During any type of trauma, neurotransmitters in the brain set off the release of a series of chemicals:

•    Catecholamines (epinephrine and norepinephrine) are responsible for the widely known "fight or flight" response and create a state of "hyperstress".

•    Coriticosteriods (glucocorticoids and cortisol) are responsible for regulating the amount of catecholamines that are released, providing energy (glucose), and assisting immune functions.

•    Oxytocin is responsible for inhibiting memory consolidation (this is also released during childbirth- women wouldn't have more than one child if they were able to accurately remember the pain!)

•    Vasopressin (anti-diuretic hormone) prevents dehydration.

•    Endogenous Opioids control pain and overwhelming emotions.

With "normal" amounts of stress, these chemicals facilitate a process that allows people to function with greater endurance, strength, immunity, and clarity. In extreme amounts of stress, however (rape, domestic violence, and other forms of victimization), these chemicals may often be released in amounts that are damaging to the brain and inhibit memory functions.

This leads us to the consolidation of traumatic memories. Our brains utilize two types of memory:

•    Explicit or declarative memory is stored verbally and logically; exemplified in our ability to reason and verbally repeat our experiences. These functions take place primarily in a part of the brain called the hippocampus.

•    Implicit or non-declarative memory is stored as senses and emotions; exemplified in our ability to recall smells, feelings, images, sounds, and tastes. These functions take place primarily in a part of the brain called the amygdala.

Research now indicates that high levels of norepinephrine, epinephrine, and endogenous opioids interfere with the storage of explicit (declarative) memory. Therefore, traumatic memories are stored in the implicit form, as emotions and senses. As practitioners, we have become accustomed to our clients remembering their experiences in pieces, and virtually "shutting down" as they attempt to re-tell their stories. Survivors become haunted by feelings and senses they know are related to the trauma, but have great difficulty clearly identifying the source(s). This promotes a vicious cycle in which the body is unable to assess danger signals and reacts to any direct or indirect reminder of the trauma as a potential re-victimization, even if the reminder is completely non-threatening. These triggers bring overwhelming emotions and sometimes flashbacks and panic attacks which in-turn cause the body to return to the emergency chemical response. These continual "flight or fight" reactions bring base-level psychobiological changes:

•    Increased levels of catecholamines (chronic hyperstress)

•    Decreased levels of glucocorticoids (poor immune functioning)

•    Decreased alpha-2 Adrenergetic receptors (less regulation of catecholamines)

•    Increased endogenous opioid levels during traumatic memory triggers (equivalent to the consumption of 8mg of morphine!)

•    Acoustic startle response: (ACR) Survivors of trauma are easily trigger by loud noises or surprises sounds. While other's may "jump" only the first couple of times they hear a loud noise, trauma survivors often startle with each and every repeat of the noise.

Additionally, preliminary research of trauma survivors has shown they have a reduction of their hippocampal volume (memory passageways) ranging between 5 and 18%. The hippocampus is a small, seahorse shaped section deeply embedded in the brain; it is responsible for managing and integrating declarative (explicit) memory functions. This reduction not only affects survivors ability to recall the trauma in an integrated and clear manner; their regular memory functions (short-term memory and reasoning abilities) may be impaired as well.

Is there hope for recovery? The good news is YES! There are pathways out of the cycle of psychobiological trauma triggers. One of our goals in working with survivors should be to assist them to integrate their memory functions so that they can recall the trauma verbally and lessen the immobilizing emotional/sensory responses. There are some excellent new techniques available that seem to accomplish this: TIR (Traumatic Incident Reduction) and EMDR (Eye Movement Desensitization Reprocessing). TIR is especially important since it can be practiced by non-licensed individuals, is completely client-centered, and has almost no risks when practiced correctly. EMDR requires that the practitioner be licensed or license-eligible and must be used carefully as part of a comprehensive treatment plan. Additionally, survivors can do any or all of the following to promote their own recovery process:

•    Within 24-48 hours after the trauma (or after a flashback) survivors can exercise vigorously to help flush the toxic chemicals from their systems. Getting their heart rates up and sweating a lot will be very helpful. Exercise also emits endorphines which helps to alleviate symptoms of depression and builds the immune system. In addition to exercise, drinking large amounts of water and eating fruits and vegetables continues to flush toxins from the body.

•    Write about their experiences of victimization. This helps to integrate the implicit and explicit memory functions.

•    Engage in memory building exercises (learn something new!) Every time people learn, they strengthen their dendrites which transmit and categorize information in their brains. Since short attention spans are common in trauma survivors, it is helpful to review new information in short increments of time.

•    Try biofeedback or relaxation techniques. Biofeedback teaches people to control biological functions. This can help to alleviate states of chronic stress that have been caused by the catecholamines.

Because this information is so new, we are constantly gaining further insights into the understanding and treatment of trauma survivors. Dr. Bessel van der Kolk, has written several excellent reviews of the literature, one of which is entitled  "The Body Keeps the Score:  Memory and the Evolving Psychobiology of Post-traumatic Stress ". A great deal of information is regularly updated on the Internet; Dr. Charles Figley's electronic Journal of Traumatic Stress  is extremely informative.

Those who share my excitement in this knowledge are welcome to  contact me for further resources.