Association of intelligence with severity of posttraumatic stress disorder symptoms in Vietnam Combat veterans

Am J Psychiatry. 1995 Jun;152(6):936-8. doi: 10.1176/ajp.152.6.936.


Objective: The purpose of this study was to determine whether intelligence predicts variance in posttraumatic stress disorder (PTSD) symptoms beyond that predicted by extent of combat exposure.

Method: The subjects were 105 male Vietnam combat veterans. They completed the Mississippi Scale for Combat-Related Posttraumatic Stress Disorder, the Combat Exposure Scale, and the Shipley Institute for Living Scale, a measure of general intelligence. Number of years of education was recorded for each subject.

Results: Multiple regression analyses revealed that estimated full-scale IQ significantly predicted variance in PTSD symptoms beyond that predicted by extent of combat exposure. The lower a subject's intelligence, the more severe were his PTSD symptoms.

Conclusions: Cognitive variables may affect the ability to cope with trauma, thereby affecting whether a person develops chronic PTSD.

MeSH terms

  • Humans
  • Intelligence Tests* / statistics & numerical data
  • Male
  • Probability
  • Severity of Illness Index
  • Stress Disorders, Post-Traumatic / diagnosis*
  • Stress Disorders, Post-Traumatic / psychology
  • Veterans / statistics & numerical data
  • Vietnam