Those with affective problems only once do not show risk of lower cognitive state.
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Recurrence, rather than timing, of problems is more predictive.
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These associations remain even when controlling for prior childhood cognition.
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The risk of lower cognitive state is already manifest in early old age (age 69).
Abstract
Background
Affective problems increase the risk of dementia and cognitive impairment, yet the life course dimension of this association is not clearly understood. We aimed to investigate how affective problems across the life course relate to later-life cognitive state.
Methods
Data from 1269 participants from the Medical Research Council National Survey of Health and Development (NSHD, the British 1946 birth cohort) were used. Prospectively-assessed measures of affective symptoms spanning ages 13–69 and categorised into case-level thresholds. Outcomes consisted of a comprehensive measure of cognitive state (Addenbrooke's Cognitive Examination (ACE-III)), verbal memory, and letter search speed and accuracy at age 69.
Results
Complementary life course models demonstrated that having 2 or more case-level problems across the life course was most strongly associated with poorer cognitive outcomes, before and after adjusting for sex, childhood cognition, childhood and midlife occupational position and education.
Limitations
A disproportionate loss to follow-up of those who had lower childhood cognitive scores may have led to underestimation of the strength of associations.
Discussion
Using a population-based prospective study we provide evidence that recurrent lifetime affective problems predicts poorer later-life cognitive state, and this risk can be already manifest in early old age (age 69). Our findings raise the possibility that effective management to minimise affective problems reoccurring across the life course may reduce the associated risk of cognitive impairment and decline.
