Causes and Risk Factors of PTSD

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People often use the word "traumatic" in a general sense when they are describing very stressful life events. For example, the American Psychological Association (APA) defines "trauma" as a person's emotional response to an extremely negative (disturbing) event.

However, mental health professionals define traumatic events in very specific ways. The guidelines they use have changed and continue to evolve as their understanding of what constitutes a traumatic event has increased. This understanding is especially important when they are trying to learn whether or not a person may have post-traumatic stress disorder (PTSD).

PTSD risk factors
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The DSM Definition of a Traumatic Event

Compared to previous editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM), the 5th edition more clearly details the elements of a traumatic event, particularly within the framework of diagnosing PTSD.

The DSM-5 defines PTSD triggers as exposure to actual or threatened:

  • Death
  • Serious injury
  • Sexual violation

Furthermore, the exposure must result from one or more of the following situations, in which the individual:

  • Directly experiences the traumatic event
  • Witnesses the traumatic event in person
  • Learns that the traumatic event occurred to a close family member or close friend (with the actual or threatened death being either violent or accidental)
  • Experiences first-hand, repeated, or extreme exposure to aversive (unpleasant) details of the traumatic event (does not learn about it through media, pictures, television, or movies, except for work-related events)

Signs That Someone May Have Been Through a Traumatic Event

Simply put, it depends. Even if you’re very close to the person, you might not notice the common symptoms of trauma, which can include appearing shaken up and “out of it.” A person may also dissociate or disconnect—for example, may not respond to your questions or comments, as if he or she weren’t there.

However, other signs that a person is traumatized may be easier for you to spot:

  • Anxiety, which may appear in the form of, for example, edginess, irritability, poor concentration, mood swings, “night terrors,” or panic attacks
  • Emotional outbursts or moods such as anger or sadness
  • Physical signs can manifest as a racing heartbeat, fatigue, paleness, or lethargy.

Risk Factors

Trauma exposure is the initiating factor behind PTSD, however, there could be additional influential elements to consider.

Not everyone who experiences trauma will develop post-traumatic stress disorder.

Although it is nearly impossible to determine with certainty who will experience PTSD after trauma and who won't, we can consider the following risk factors that might contribute to the likelihood of developing post-traumatic stress disorder.

Genetic Factors

Research continues to explore the role of genetics in the development of PTSD. There have been studies showing genetic influence on the development of mental health conditions such as schizophrenia, bipolar disorder, and major depressive disorder, and researchers are finding genetic influence in the development of PTSD as well.

Women are considered more likely to develop PTSD than men. The prevalence of PTSD over the lifespan has been found to be 10 percent to 12 percent among women and 5 percent to 6 percent in men.

Researchers have found among European-American females in particular, close to one-third (29 percent) of the risk for developing PTSD after a traumatic event was influenced by genetic factors. The genetic risk rate was found to be much lower in males.

The first author of the study, Dr. Laramie Duncan, concluded that "PTSD may be one of the most preventable of the psychiatric disorders." Understanding that not all people who experience trauma will develop PTSD, she shares the importance of this genetic research to be able to intervene quickly after trauma for those individuals who are identified as more genetically at risk.

Current Research

Genetic markers currently under investigation for their role in influencing the development of PTSD include those such as the serotonin transporter gene (5-HTTLPR) and genes associated with the hypothalamic-pituitary-adrenal (HPA) axis.

Additionally, there is research in the retinoid-related orphan receptor alpha (RORA) protein due to the role it plays in neuroprotection, helping protect neurons and glial cells from degenerative effects of oxidative stress, which is an impact of experiencing traumatic stress.

Societal Factors

Social support, or lack of, is a critical risk factor. Those who are limited in options for social support can be at greater risk for PTSD. After the traumatic event, the need for safe support resources is essential to help individuals process their experience in a healthy way and to regain hope through secure and safe emotional connections.

Those with more avoidant coping strategies will be less likely to utilize supportive resources or seek healthy connections after experiencing a traumatic event. People who try to generally cope with challenges in isolation may be at greater risk for developing PTSD.

Even if you do have support available, it may not be enough to curb the development of PTSD.

Biological and Neurological Factors

Two risk factors that have been shown to possibly influence the development of PTSD after trauma are IQ and neuroticism. Those who tend to score lower on IQ tests have been shown to be more susceptible to developing PTSD.

In addition, people who have greater neuroticism have shown to be more likely to have PTSD.

Neuroticism is a personality trait of people who are more likely than average to experience anxiety, feelings of guilt, worry, fear, anger, frustration, and sadness.

As mentioned previously, there is an increasing number of research studies dedicated to exploring the role of genetics in the development of PTSD. Being that PTSD does not occur in everyone who experiences a traumatic event, these continued findings help to better determine who may be at greatest risk so that interventions and treatments can be of the most help.

Post-traumatic stress disorder, along with other conditions such as major depression, is associated with decreased brain volume, particularly in the prefrontal areas. Research has shown that this decreased volume was associated with greater self-reports of anxiety in participants.

Understanding that the emotional impact of trauma can have a cumulative effect—it can be easier to understand how past traumatic experiences can be a risk factor for someone developing PTSD after a marked traumatic event.

Other Factors

Another risk factor in the development of PTSD after a traumatic event is having experienced another trauma in the past. The impact of trauma has been found to have a cumulative effect. This means that a trauma survivor who did not previously show symptoms of post-traumatic stress disorder could develop PTSD after subsequent trauma.

A history of struggling with a mental health condition prior to the traumatic event can also be a risk factor in the development of PTSD. It has been shown that existing mood disorders, anxiety-related disorders, and conduct disorder can be influential risk factors.

Life stressors are a risk factor as well. When people are currently experiencing life stressors such as divorce, financial strain, work stress, or for children who are experiencing emotional challenges at school or home, the likelihood of developing PTSD can increase.

The nature of the triggering event is something to consider as an influential factor. It has been shown that the more intense the event, such as witnessing death or extreme violence or having been injured during the traumatic event, can be a risk factor.

When someone has experienced physical pain as a result of their trauma, such as with sexual abuse, the risk of PTSD can be greater, since the physical pain is a reminder of the traumatic event.

Helping Someone Cope With a Traumatic Event

It’s tough trying to help when a friend or loved one doesn’t want to talk about what happened. It can be hard to keep making the effort to get the person to respond, especially if you feel you’re being pushed away. But you’re in a good place to help when you:

  • Understand the definition of a traumatic event
  • Can identify some of the signs
  • Are willing to keep offering help even if it's not accepted at first

Remember, your caring support after a traumatic event may make a big difference in how well and how fast the traumatized person recovers.

10 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading
  • “Posttraumatic Stress Disorder.” Trauma Symptoms, Causes, and Effects. American Psychiatric Association, American Psychiatric Publishing (2013)

By Matthew Tull, PhD
Matthew Tull, PhD is a professor of psychology at the University of Toledo, specializing in post-traumatic stress disorder.