functions related primarily to PTSD:
1. Key Brain Structures
• Hippocampus: Responsible for consolidating memories (forming and storing new memories) and reconsolidating old memories (retrieving a memory from long-term storage, bringing it into working memory, and then re-storing it). The hippocampus has a high number of stress hormone receptors, which is critical for the proper functioning of the stress response.
• Amygdala: Detects threats and alerts other brain structures and systems within the body.
• Prefrontal Cortex: Involved in a variety of complex executive functions, including planning, analysis, judgement, and decision-making.
• Hypothalamic Pituitary-Adrenal Axis (HPA axis): The HPA axis a term used to represent the interaction between the hypothalamus, pituitary gland, and the adrenal glands. The HPA axis plays an important role in regulating the stress response (turning it on and off).
2. Hormones and Neurotransmitters:
• Cortisol: This hormone plays a critical role in activating, as well as deactivating the stress response.
• Adrenaline and norepinephrine: Stress hormones that also act as neurotransmitters and are highly involved in the stress response.
• GABA: The brain’s main inhibitory neurotransmitter and helps inhibit amygdala and nervous system activity.
• Glutamate: The brain’s main excitatory neurotransmitter.
It is generally accepted that PTSD is caused by a dysregulation in several stress-mediating systems as a result of exposure to trauma, but exactly how and why this dysregulation occurs remains unclear. What we do know is that these structural and functional differences cause observable effects, including:
• Exaggerated stress response
• Inability to extinguish fears associated with the traumatic event
• Impaired ability to discriminate between safe and unsafe stimuli
• Inability to suppress unwanted thoughts and memories
• Difficulty regulating emotions and coming down from high emotional states (such as anxiety and anger)
• Periods of dissociation (out-of-body experiences, not knowing where you are or how you got there, etc.)
• Difficulty with concentration, attention, learning, and memory
• Increased physical ailments
Understanding how things become dysregulated with PTSD is problematic because there are so many systems involved, and the neurological, biochemical, and genetic influences have not yet been fully unravelled. Contradictory research findings further compound the problem, making it nearly impossible to draw clear conclusions.
PRACTICAL EXERCISE — CONSIDER THE EFFECTS OF PTSD
Understanding the functional and structural brain changes in PTSD can relieve some of the guilt and shame that can be experienced by those with PTSD. When someone believes their situation is their fault or that they are just not strong enough to fight it, it may help to know there is an organic, physiological explanation. The more we understand these biological factors, the more we can learn effective ways to influence them in positive ways. In your journal, describe how you feel about the measurable physiological changes that are affecting you.
REFLECTIVE QUESTIONS
• On a scale of 1 to 5, how possible do you believe it is to positively influence your nervous system?
• How might you experience life differently if your most distressing effects were no longer present? Imagine your life without PTSD and what that would look like. How would your life be if you woke up tomorrow and PTSD had magically disappeared overnight? Create a clear vision of this possibility in your mind.
• PTSD has already robbed you of a lot of precious time and energy. Consider what else you might lose if your nervous system stays in survival mode. Make a list.
RISK FACTORS
Imagine a police officer arrives on a crime scene moments after a serial killer has removed the kidneys of a man he has just murdered. By the time the officer arrives, the killer has already been arrested by the first officers on the scene, and his bloody hands are in handcuffs. As the officer examines the area, he discovers another room where he finds several more dead bodies.
Now imagine a second scenario where a medical student is in the operating room observing a potentially life-saving kidney transplant. As it sometimes happens, things go wrong and the patient dies. Let’s further suppose the medical student then goes to the morgue and passes several corpses before finding the pathologist.
The police officer and medical student are essentially being exposed to very similar scenes. Considering the two scenarios, who would you predict would be at highest risk for developing PTSD?
You may have guessed the police officer, which would be a good guess. However, the risk and vulnerability factors associated with PTSD are multifaceted and unique to each individual, making it very difficult to predict who will develop PTSD. It may be the officer or the student, or it could be the surgeon, a nurse who was in the operating room, or a family member of one of the murder victims. The truth is, no one knows exactly why one person will develop PTSD after a traumatic event while another will not. To complicate matters, trauma responses not only vary from person to person, but also vary within the same person over time. In other words, even if you’ve moved through trauma in a certain way in the past, it doesn’t mean you will move through it in the same way if exposed to a similar trauma in the future. Many first responders have told me things like, “I’ve seen worse things before, I don’t understand why I can’t get over this one,” or “I’ve handled similar situations so many times. Why is this one still haunting me?”
There are so many factors and variables at play in any given situation affecting a person’s reaction to a traumatic event. Why some people develop PTSD while others do not, or why one person develops PTSD in response to an event that they’ve dealt with before, is not an easy question to answer, and in fact, it cannot be fully answered with the information that is currently available. While it is impossible to predict who will develop PTSD, or when, there are certain factors that increase a person’s risk. Some of these factors revolve around the nature of the traumatic event itself, while others have to do with the person’s past experiences, conditioning, and genetics. Keeping in mind that we are all different as individuals and each person’s experience has unique aspects, here are some of the risk factors, in no particular order:
• Previous exposure to stress, trauma, and adverse experiences early in life
• Co-occurring physical or psychiatric conditions (two conditions occurring at the same time)
• Neurobiological changes (i.e., a smaller hippocampus, larger amygdala, low cortisol at time of trauma, persistently high norepinephrine)
• Genetic predisposition (family history of PTSD)
• Warfare
• History of sexual assault
• Bullying, workplace, or social harassment
• Previous mental, emotional, or physical abuse
• Gender: women are more likely to develop PTSD than men
• Isolation and lack of social, family, and work supports
• Type of trauma
• Severity of the trauma: the more extreme, prolonged, or personal, the more increased the risk for PTSD. For example, a traumatic experience such as rape increases risk of PTSD in comparison to a natural disaster.
• Proximity to the trauma: how close you were physically as well as emotionally. For example, if you are exposed to the death of child that resembles your own child, it will be closer to you emotionally.
•