Brain Fog and Cognitive Dysfunction in Posttraumatic Stress Disorder: An Evidence-Based Review

Brahm D Sanger,1,2,* Arij Alarachi,1,2,* Heather E McNeely,2,3 Margaret C McKinnon,2– 4 Randi E McCabe2,3 1Department of Psychology, Neuroscience, and Behaviour, McMaster University, Hamilton, ON, Canada; 2St Joseph’s Healthcare Hamilton, Hamilton, ON, Canada; 3Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada; 4Homewood Research Institute, Homewood Health Centre, Guelph, ON, Canada*These authors contributed equally to this workCorrespondence: Randi E McCabe, Anxiety Treatment and Research Clinic, St Joseph’s Healthcare Hamilton, 100 West 5th Street, Hamilton, ON, L9C 0E3, Canada, Email [email protected]: The term “brain fog” has long been used both colloquially and in research literature in reference to various neurocognitive phenomenon that detract from cognitive efficiency. We define “brain fog” as the subjective experience of cognitive difficulties, in keeping with the most common colloquial and research use of the term. While a recent increase in use of this term has largely been in the context of the post-coronavirus-19 condition known as long COVID, “brain fog” has also been discussed in relation to several other conditions including mental health conditions such as post-traumatic stress disorder (PTSD). PTSD is associated with both subjective cognitive complaints and relative deficits on cognitive testing, but the phenomenology and mechanisms contributing to “brain fog” in this population are poorly understood. PTSD psychopathology across cognitive, affective and physiological symptom domains have been tied to “brain fog”. Furthermore, dissociative symptoms common in PTSD also contribute to the experience of “brain fog”. Comorbid physical and mental health conditions may also increase the risk of experiencing “brain fog” among individuals with PTSD. Considerations for the assessment of “brain fog” in PTSD as part of psychodiagnostic assessment are discussed. While standard psychological intervention for PTSD is associated with a reduction in subjective cognitive deficits, other cognitive interventions may be valuable when “brain fog” persists following PTSD remission or when “brain fog” interferes with treatment. Limitations of current research on “brain fog” in PTSD include a lack of consistent definition and operationalization of “brain fog” in the literature, as well as limited tools for measurement. Future research should address these limitations, as well as further evaluate the use of cognitive remediation as an intervention for “brain fog”.Keywords: subjective cognition, cognitive complaints, mental fatigue, trauma