Research Summaries
Why was the study done?
Police are regularly exposed to dangerous and stressful situations, increasing their risk of developing posttraumatic stress disorder (PTSD). PTSD is a mental health disorder characterized by clusters of symptoms, including:
- Intrusive symptoms like recurring thoughts, distressing dreams, and flashbacks;
- Avoidance symptoms like avoiding the location of the trauma or thoughts of the trauma;
- Negative changes to thoughts and mood like inability to remember the traumatic event or persistent poor mood; and
- Changes to reactivity like hypervigilance or trouble sleeping.
PTSD is also associated with changes in cognitive abilities like attention, working memory, and executive functioning. However, little research has been done with police to determine what, if any, cognitive impairments they experience when diagnosed with PTSD.
The current study:
- examined cognitive functioning in police with and without PTSD;
- examined the clinical significance of the performance of officers with PTSD; and
- explored the relationship between PTSD symptoms and cognitive functioning.
What was done in the study?
Participants were all French-speaking officers currently or previously employed in Quebec. The 61 participants (31 with PTSD or trauma-related and stressor-related disorders; 30 with no trauma-related disorders) were part of a larger study on PTSD treatment. Officers without trauma-related disorders (the control group) were matched for age and sex with the PTSD group. Each participant went through a clinical assessment, completed self-report questionnaires, and a set of neuropsychological tests. The researchers chose the neuropsychological tests to assess six cognitive skills, including:
- Processing speed;
- Attention;
- Executive functioning (including the ability to make decisions, regulate self, and focus attention);
- Verbal learning and memory;
- Working memory; and
- Lexical Access (the ability to attach meaning to words or names).
What did we find out?
Note: “significance” means an outcome cannot be attributed to chance or random factors
- On average, officers in the control group outperformed the PTSD group on all neuropsychological tests.
- The PTSD group had significantly lower scores on tests of executive functioning, lexical assess, and verbal learning and memory.
- Lower scores were also seen in the PTSD group for processing speed, attention and working memory, but they didn’t reach the level of significance.
- PTSD group members who experienced more intrusive symptoms had significantly poorer attention, working memory, processing speed, and executive functioning scores.
- PTSD group members who had more avoidance symptoms had significantly poorer processing speed.
- Those in the PTSD group who were not working showed significantly lower performance than those who were currently working. There were also differences, though non-significant, in attention and working memory.High scores on Depression measures appeared to contribute to these results.
- Only one person in the PTSD group had a “clinically significant” functional impairment, with 52% of the group experiencing impairment on an average of 1.5 subtests and 48% showing no impairment.
Where do we go from here?
The data provided by this study showed that there appear to be mild cognitive impairments in several domains for officers with PTSD. However, it is interesting that even though there were significant differences between the control and PTSD groups for most officers with PTSD, cognitive performance still fell within the normal range. It is likely that police officers typically operate at the higher range of normal functioning. This result highlights the importance of neuropsychological testing in clinical management, since subtle changes might be missed without detailed testing. It is also important to note that the presence of Depression in addition to PTSD had a cumulative negative impact on cognitive performance. PTSD cannot be treated in isolation; all factors need to be understood and accounted for to provide the best care.
The original wording of the study was changed and condensed for the current research summary.
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Original Study
Bisson Desrochers, A., Rouleau, I., Angehrn, A., Vasiliadis, H-M., Saumier, D., & Brunet, A. (2021). Trauma on duty: Cognitive functioning in police officers with and without posttraumatic stress disorder (PTSD). European Journal of Psychotraumatology, 12, 1959117. https://www.tandfonline.com/doi/full/10.1080/20008198.2021.1959117
Summary prepared by Kossick, E. Edited and reviewed by Barootes, B. & Brunet, A.