Clouston · Alzheimer's & dementia (Amsterdam, Netherlands) 2016 · longitudinal cohort study · n=818

Cognitive impairment among World Trade Center responders: Long-term implications of re-experiencing the 9/11 terrorist attacks.

Cited 85 times in the scientific literature.

Level 3 - non-randomized controlled study

Prospective cohort study linking longitudinal symptom inventories to subsequent cognitive screening

PubMed 27626057 · doi:10.1016/j.dadm.2016.08.001 · record verified 2026-08-29

What was done

A sample of 818 World Trade Center responders attending annual monitoring visits between January 2014 and April 2015 were screened for cognitive impairment and dementia using the Montreal Cognitive Assessment. Researchers analyzed concurrent diagnoses of PTSD and major depressive disorder, along with serial PTSD and depressive symptom inventories collected prospectively since 2002, in relation to cognitive impairment.

What was found

Approximately 12.8% of responders had scores indicative of cognitive impairment and 1.2% had scores indicating possible dementia. Current PTSD and major depressive disorder were associated with cognitive impairment. Longitudinally, re-experiencing symptoms were consistently associated with cognitive impairment (aRR = 2.88, 95% confidence interval = 1.35-6.22), while longitudinal increases in other PTSD and depressive symptoms before screening were evident only among those with cognitive impairment.

Why it matters

This study extends findings from military veterans to civilian responders, showing that chronic PTSD re-experiencing symptoms consistently predict cognitive impairment 14 years after trauma exposure.

Limits

Cognitive status was evaluated using a brief screening tool rather than full neuropsychological testing or formal clinical diagnostic criteria. The sample was restricted to responders attending routine monitoring visits, introducing potential selection bias, and the abstract does not report baseline cognitive measures prior to screening or distinguish psychological trauma from concurrent toxic physical exposures.

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