Complex Real Life-Related Prospective Memory in Soldiers with and Without Post-Traumatic Stress Disorder

Objective: Posttraumatic stress disorder (PTSD) is known to influence memory functions in a complex fashion. However, little is known about the impact of PTSD on future directed mnemonic functions like prospective memory (PM). 

Methods: The present study aimed at examining performance of 13 soldiers with PTSD, 12 without PTSD and 21 non-military controls without PTSD across different phases of a real life-related PM paradigm. In addition, neuropsychological tests of memory and the influence of salivary cortisol levels on memory performance were
assessed.
Results: Soldiers with PTSD performed significantly worse during the planning and retrieval phase of time- and event-dependent PM compared to the non-military controls, but not to soldiers without PTSD. Moreover, PTSD symptom severity correlated negatively with PM retrieval. In soldiers without PTSD time- and eventdependent PM was significantly declined during retrieval phase compared to the non-military controls. Significantly decreased salivary cortisol levels were detected only for soldiers with PTSD. Standard neuropsychological assessment showed significantly impaired working- and retrospective long-term memory in both
soldiers with and without PTSD.
Conclusion: Our results indicate for the first time that exposure to combat-related stress may have selective deteriorating effects on real-life-related PM and other memory functions in the absence of a PTSD diagnosis. We conclude that stress-related alterations of memory functions in soldiers may not only be related to
PTSD-related changes in cortisol metabolism. Rather, additional neuropeptides and/or neurohormones may be involved in the emergence of memory dysfunctions resulting from combat-related stress.