Post-traumatic stress disorder and memory function in older adults exposed to civilian conflict: findings from the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA)

Research with veterans, refugees and other trauma-exposed groups has identified a link between post-traumatic stress disorder (PTSD) and deficits in memory. This study sought to determine whether similar associations can be observed in a large, population-representative sample of older adults with high levels of exposure to conflict amongst older adults in Northern Ireland (NI). Using data from the Northern Ireland COhort for the Longitudinal study of Ageing (NICOLA), we assessed whether the presence of PTSD was associated with poorer performance on tasks of global cognition, immediate and delayed verbal recall, executive function, verbal fluency and two tests of prospective memory. Participants were 2142 community dwelling adults, resident in NI and aged 50 and over. The NI weighted prevalence of current PTSD was 4.74 %, which is high relative to other international estimates. Nearly 60 % of those with PTSD reported the NI Troubles as their self-reported worst traumatic exposure, despite the height of the conflict occurring decades before, suggesting long-term consequences of the civil conflict. Individuals with PTSD recalled approximately half a word less than those without on tests of verbal recall and scored lower on global cognitive assessments: Mini Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA), after accounting for sociodemographic characteristics. However, this effect was attenuated after further adjusting for health behaviours and current depression. The findings suggest an effect of trauma on cognitive function at a population level. Future research should explore the nature of this relationship over time.