Posttraumatic Stress Disorder and Inflammation: Untangling Issues of Bidirectionality

Area of Science:

• Psychiatry
• Immunology
• Epidemiology

Background:

• Posttraumatic stress disorder (PTSD) is increasingly associated with systemic inflammation.
• The causal nature of this relationship (bidirectional, unidirectional, or correlational) is debated.
• Understanding this link is vital for PTSD risk assessment and understanding its impact on physical health.

Purpose of the Study:

• To review longitudinal evidence on the PTSD-inflammation relationship.
• To clarify the directionality and causality between PTSD and inflammation.
• To recommend methods for future research and discuss intervention implications.

Main Methods:

• Systematic review of longitudinal studies examining PTSD and inflammation.
• Assessment of evidence regarding inflammation as a risk factor for PTSD.
• Evaluation of studies investigating PTSD's effect on subsequent inflammation.

Main Results:

• Limited longitudinal studies rigorously assess the directionality of the PTSD-inflammation link.
• Some evidence suggests pretrauma or acute inflammation elevates PTSD risk.
• Findings on PTSD influencing subsequent inflammation are mixed, with high variability in study designs and measures.

Conclusions:

• The causal direction between PTSD and inflammation is not definitively established.
• Further research employing robust statistical and study designs is needed.
• Clarifying causality may inform novel intervention and treatment strategies for PTSD.