ETIOLOGY

Although PTSD is always triggered by an external event, it may have roots in one’s biology as much as experience. Researchers suspect that genetics may contribute to a person’s susceptibility to PTSD through an interaction with environmental factors.

Pathophysiology

The pathophysiology of PTSD is unclear, but some studies have found that PTSD frequently leads to changes in the anatomy and neurophysiology of the brain. These changes include:

  • Reduced size of the hippocampus, which is probably both a predisposing factor and result of trauma
  • Overly reactive amygdala, which is involved in processing emotions and modulating the fear response
  • Smaller and less responsive medial prefrontal cortex, which exhibits inhibitory control over the stress response and emotional reactivity of the amygdala

Alterations in neurohormonal and neurotransmitter functioning have also been found:

  • Normal to low circulating levels of cortisol despite ongoing stress and elevated levels of corticotropin releasing factor (CRF)
  • Hyperactivity of the sympathetic branch of the autonomic nervous system causing changes in heart rate, blood pressure, skin conductance level, and other psychophysiological measures
  • Elevated noradrenergic reactivity to pharmacological challenges
  • Altered functioning of other neurotransmitter systems, including serotonin, gamma aminobutyric acid (GABA), glutamate, neuropeptide Y, and endogenous opioids

Another theory, the Dual Representation Theory, highlights the presence of two separate systems for memory:

  • Verbally accessible memory is recorded in the hippocampus and later in general brain memory storage and is able to be modified by reflection. This is characteristic of most nontraumatic memories.
  • Situationally accessible memory is nonverbal and associated with very strong emotions that engage the amygdala. This is where traumatic memories tend to be stored. They are harder to process, are readily triggered by associations, and more likely to cause emotional distress when activated.
    (Sareen, 2020; Gore, 2018)

Risk Factors

Factors that make individuals more likely to develop PTSD after a traumatic event may include:

  • Female gender
  • Younger age at time of trauma
  • Lower education
  • Lower socioeconomic status
  • Being separated, divorced, or widowed
  • Lack of a good support system
  • Previous trauma
  • Experiencing intense or long-lasting trauma
  • Initial severity of reaction to the trauma
  • Drug, alcohol, and other substance misuse
  • General childhood adversity
  • Personal and family psychiatric problems, including anxiety or depression
  • Reported childhood abuse
  • Occupation choice (e.g., firefighter, EMS, military, police)
  • Sleep disorders such as insomnia or sleep apnea
    (Sareen, 2020; PTSD Alliance, 2020)

Resilience

Many people are affected by traumatic events, but a majority of them recover from stress reactions and do not go on to develop PTSD. The ability to recover quickly from or adjust easily to traumatic events involves a degree of resilience.

Resilience is the process of adapting well in the face of adversity, trauma, tragedy, threats, or significant sources of stress. Resilience involves “bouncing back” from difficult experiences, but it can also involve profound personal growth, allowing an individual to grow and improve life.

Resilience involves behaviors, thoughts, and actions that can be learned and developed. Increasing resilience takes time and intention, focusing on four major components: connection, wellness, healthy thinking, and meaning. These include:

  • Building connections with others
  • Fostering wellness of body and mind
  • Finding purpose and meaning
  • Learning healthy ways of thinking (e.g., keeping things in perspective)
  • Seeking professional help when needed
    (APA, 2020)