top of page

Epidemiology & Prevalence of PTSD

Introduction to Epidemiology of PTSD:

Posttraumatic Stress Disorder (PTSD) is a significant mental health condition that arises following exposure to traumatic events. Understanding the epidemiology of PTSD is essential for clinicians, researchers, and public health officials to develop effective prevention and treatment strategies. This section provides a detailed overview of the prevalence, risk factors, and types of trauma associated with PTSD, highlighting the diverse impact of trauma on different populations and the critical need for targeted mental health interventions.

Prevalence and Incidence:

In North America, the lifetime prevalence of PTSD ranges from 6.1% to 9.2% among adults, with annual prevalence rates of 3.5% to 4.7%. These statistics underscore the significant burden of PTSD in the general population. An international community-based survey covering 24 countries found the conditional probability of PTSD to vary considerably following different types of traumatic events, highlighting the extensive and diverse impact of trauma globally.

Variations in PTSD Prevalence:

  • General Population: A U.S. study involving 5,692 respondents revealed that 82.7% had experienced severe trauma, with 8.3% subsequently developing lifetime PTSD. In primary care settings, 65% of patients reported severe trauma exposure, and 12% of these developed PTSD. This indicates that trauma exposure is widespread, and a significant portion of those exposed develop PTSD.

  • Native American Populations: Native Americans living on reservations exhibit higher PTSD rates compared to the general U.S. population. Lifetime prevalence in large Native American samples ranged from 14.2% to 16.1%. A systematic review found that indigenous peoples in the U.S., Canada, and Latin America had 1.4 times greater odds of lifetime PTSD compared to nonindigenous populations. This highlights the need for targeted mental health services for these communities.

  • Refugee Populations: Refugees from countries with endemic traumatic stress have notably high PTSD rates. For instance, 62% of Cambodian refugees who resettled in the U.S. were found to meet PTSD criteria two decades after resettlement. This underscores the long-lasting impact of severe and chronic trauma experienced by refugees.

International Epidemiology of PTSD:

  • Australia: A national survey of 10,641 Australians indicated a lifetime PTSD prevalence of 1.0%.

  • Middle-Income Countries: A World Health Organization study reported lifetime PTSD prevalence rates of 2.3% in upper-middle-income countries and 2.1% in lower-middle-income countries. These figures suggest a lower prevalence of PTSD in middle-income countries compared to North America, which may reflect differences in exposure to trauma, cultural factors, or healthcare systems.

Risk Factors for PTSD:

  • Pre-Trauma Risk Factors: Factors that increase the likelihood of developing PTSD include prior trauma exposure, lower educational attainment, lower socioeconomic status, childhood adversity, and a personal or family history of psychiatric conditions. These risk factors highlight the importance of early intervention and support for at-risk individuals.

  • Demographic Factors: Gender and race also play significant roles in PTSD risk. Females are twice as likely to develop PTSD compared to males, even after adjusting for trauma exposure. Additionally, inadequate social support is a significant risk factor, emphasizing the importance of social networks and community support in mitigating PTSD risk.

Impact of Trauma Type and Exposure:

  • Intentional vs. Unintentional Trauma: The nature of the traumatic event significantly influences the risk of developing PTSD. Intentional traumas, such as assaults or combat, have a stronger association with PTSD than unintentional or non-assaultive traumatic events. This distinction underscores the severe psychological impact of interpersonal violence and conflict.

  • Duration and Severity of Exposure: Prolonged exposure to trauma is associated with a higher risk of PTSD. The severity of the initial reaction to trauma also plays a crucial role in the development of the disorder. These findings suggest that early and intensive intervention following trauma exposure can be critical in preventing PTSD.

Examples of Trauma Types Leading to PTSD:

  • Sexual Assault: Sexual assault is the most frequent type of trauma experienced by women with PTSD. In a nationally representative sample of 4,008 U.S. women, the lifetime prevalence of PTSD was 12.3%. Among these women, 32% had been raped, and 31% had experienced a sexual assault other than rape. This highlights the severe and lasting impact of sexual violence on mental health.

  • Mass Conflict and Displacement: A meta-analysis of 145 studies involving 64,332 refugees and other conflict-affected individuals found a mean PTSD prevalence rate of 30.6%. Factors contributing to higher PTSD rates included reported torture, cumulative exposure to potentially traumatic events, shorter time since conflict, and higher levels of political terror. These findings underscore the need for comprehensive mental health services for conflict-affected populations.

  • Combat: PTSD following combat injury is strongly correlated with the extent of injury and the presence and severity of traumatic brain injury. Studies have shown that soldiers with severe physical problems post-injury are at greater risk of developing PTSD. This emphasizes the importance of addressing both physical and psychological injuries in military populations.

Specific Trauma Events:

  • Interpersonal-Network Traumatic Experiences: Events such as the unexpected death of a loved one, life-threatening illness of a child, and other significant traumatic events affecting close individuals account for 30% of PTSD cases. This category highlights the profound impact of traumatic events within personal relationships.

  • Interpersonal Violence: Childhood physical abuse, witnessing interpersonal violence, and physical assault comprise about 12% of PTSD cases. These statistics emphasize the long-term psychological effects of violence experienced during formative years.

  • Exposure to Organized Violence: Refugees, kidnapped individuals, and civilians in war zones represent about 3% of PTSD cases. This category underscores the severe impact of systemic and chronic violence on mental health.

  • Participation in Organized Violence: Combat exposure, witnessing death or serious injury, and causing death or serious injury account for 11% of PTSD cases. This highlights the psychological burden on individuals directly involved in violent conflicts.

  • Other Life-Threatening Traumatic Events: Severe motor vehicle collisions, natural disasters, and toxic chemical exposures represent 11% of PTSD cases. These events illustrate the wide range of traumatic experiences that can lead to PTSD.

Understanding these epidemiological factors is crucial for developing targeted interventions and support systems for populations at risk. Identifying high-risk groups and the types of trauma that most frequently lead to PTSD can guide clinical practice and public health initiatives to mitigate the impact of this disorder. These insights emphasize the need for comprehensive, culturally sensitive, and trauma-informed care for affected individuals and communities.



This review of the epidemiology of PTSD is based on data and resources from APA and platforms. APTSDA is not responsible for the accuracy or use of this information in clinical practice.


  • Chivers-Wilson, K. A. (2006). Sexual assault and posttraumatic stress disorder: A review of the biological, psychological and sociological factors and treatments. McGill Journal of Medicine: MJM: An International Forum for the Advancement of Medical Sciences by Students, 9(2), 111–118.

  • Goldstein, R. B., Smith, S. M., Chou, S. P., Saha, T. D., Jung, J., Zhang, H., Pickering, R. P., Ruan, W. J., Huang, B., & Grant, B. F. (2016). The epidemiology of DSM-5 posttraumatic stress disorder in the United States: Results from the National Epidemiologic Survey on Alcohol and Related Conditions-III. Social Psychiatry and Psychiatric Epidemiology, 51(8), 1137–1148.

  • Kessler, R. C., Berglund, P., Demler, O., Jin, R., Merikangas, K. R., & Walters, E. E. (2005). Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication. Archives of General Psychiatry, 62(6), 593–602.

  • Koenen, K. C., Ratanatharathorn, A., Ng, L., McLaughlin, K. A., Bromet, E. J., Stein, D. J., Karam, E. G., Meron Ruscio, A., Benjet, C., Scott, K., Atwoli, L., Petukhova, M., Lim, C. C. W., Aguilar-Gaxiola, S., Al-Hamzawi, A., Alonso, J., Bunting, B., Ciutan, M., de Girolamo, G., … Kessler, R. C. (2017). Posttraumatic stress disorder in the World Mental Health Surveys. Psychological Medicine, 47(13), 2260–2274.

  • Kroll, J. (2003). Posttraumatic symptoms and the complexity of responses to trauma. JAMA, 290(5), 667–670.

  • Resnick, H. S., Kilpatrick, D. G., Dansky, B. S., Saunders, B. E., & Best, C. L. (1993). Prevalence of civilian trauma and posttraumatic stress disorder in a representative national sample of women. Journal of Consulting and Clinical Psychology, 61(6), 984–991.

  • Sareen, J., Erickson, J., Medved, M. I., Asmundson, G. J. G., Enns, M. W., Stein, M., Leslie, W., Doupe, M., & Logsetty, S. (2013). Risk factors for post-injury mental health problems. Depression and Anxiety, 30(4), 321–327.

  • Stein, D. J., Seedat, S., Iversen, A., & Wessely, S. (2007). Post-traumatic stress disorder: Medicine and politics. Lancet (London, England), 369(9556), 139–144.


Rated 0 out of 5 stars.
No ratings yet

Add a rating
Featured Posts
Recent Posts
Search By Tags
bottom of page