Role of Intelligence in Posttraumatic Stress Disorder Development: A Systematic Review.

Posttraumatic stress disorder (PTSD) has been associated with a range of cognitive alterations; however, the relationship between PTSD and intelligence remains unclear. The aim of this systematic review was to examine potential differences in intelligence associated with exposure to traumatic events and/or a diagnosis of PTSD in adults aged 18 years and older. A systematic search was conducted across three major academic databases-PsycINFO, MEDLINE, and Web of Science-to identify empirical studies assessing intelligence or closely related cognitive constructs in individuals with PTSD or a history of trauma exposure. After applying predefined inclusion criteria, 12 studies were included in the review. Intelligence was assessed using various psychometric instruments, encompassing both global intelligence measures and specific domains such as verbal intelligence and vocabulary. Overall, the findings consistently indicated a negative association between intelligence and PTSD, with lower intelligence scores more frequently observed among individuals with PTSD or significant traumatic exposure. Due to the correlational design of the studies included, causal relationships cannot be established. Consequently, it remains unclear whether intelligence is affected by PTSD or whether higher intelligence may serve as a protective factor against the development or severity of the disorder. From an intelligence research perspective, these findings highlight cognitive ability as a key factor associated with vulnerability and resilience in trauma-related psychopathology.