Prevalence of Traumas and PTSD Among Individuals Adjudicated Not Guilty by Reason of Insanity

J Am Acad Psychiatry Law. 2021 Jun;49(2):194-201. doi: 10.29158/JAAPL.200062-20. Epub 2021 Feb 12.


Trauma and posttraumatic stress disorder (PTSD) are common among psychiatric and criminal populations, yet there have been few studies among forensic psychiatric populations and no known studies have specifically examined insanity acquittees. This study aimed to identify the prevalence of trauma and to assess recognition of PTSD in forensic settings. Using a cross-sectional self-report survey methodology, we examined traumas, adverse childhood experiences (ACEs), and PTSD in insanity acquittees (n = 107). Most insanity acquittees experienced trauma (86%, averaging 11 events) and ACEs (76%, averaging 3 types). The most commonly experienced traumas were sudden death of a loved one, witnessed death or serious injury, adult physical assault, and motor vehicle accident. Women were significantly more likely to experience any ACE (especially witnessing domestic violence, household members with mental illness, emotional abuse, and emotional neglect) and adult sexual assault. PTSD prevalence was 25 percent, with 97 percent of cases being previously undiagnosed. Sexual traumas and younger age were significantly associated with PTSD. These results suggest that insanity acquittees have high levels of trauma, ACEs, and PTSD. While PTSD was about seven times more common than in previous findings in the general population, it frequently goes undiagnosed in forensic settings. Potential explanations and implications of our findings are discussed.

Keywords: ACE; NGRI; PTSD; forensic; insanity; trauma.

MeSH terms

  • Adult
  • Adult Survivors of Child Adverse Events / psychology*
  • Adult Survivors of Child Adverse Events / statistics & numerical data
  • Cross-Sectional Studies
  • Exposure to Violence / psychology*
  • Exposure to Violence / statistics & numerical data
  • Female
  • Forensic Psychiatry
  • Hospitals, Psychiatric
  • Humans
  • Insanity Defense*
  • Male
  • Michigan / epidemiology
  • Prevalence
  • Self Report
  • Stress Disorders, Post-Traumatic / epidemiology*