# Longitudinal associations of psychological distress with subsequent cognitive decline and dementia: a multi‐cohort study

## TL;DR

This study finds that psychological distress is linked to lower cognitive levels and higher dementia risk in later life, based on data from five UK studies.

## Contribution

The study provides new evidence on the longitudinal associations between psychological distress and cognitive decline across different age groups.

## Key findings

- Higher psychological distress was associated with lower cognitive levels and increased dementia risk.
- Both persistent and intermittent distress were linked to poorer cognitive outcomes.
- Associations were strongest for distress assessed at ages 55-64 and 65-75, not 45-54.

## Abstract

Psychological distress has been linked with cognitive impairment. However, whether the relationship is causal, reflects preclinical dementia neuropathology, or confounding by common causes remains unclear.

In five UK longitudinal studies, we examined associations of psychological distress with subsequent cognition using linear and mixed effects models, and dementia using logistic regression. We examined variation by age‐at‐assessment, severity, and distress persistence, combining study‐specific estimates using two‐stage individual participant data meta‐analysis.

Pooling across studies (N = 24,564), greater baseline psychological distress was associated with lower subsequent cognitive level (β = −0.03 [95% confidence interval [CI]: −0.06; −0.01]; I
2 = 70%), and dementia (odd ratio [OR] = 1.1 [1.0; 1.2]; I
2 = 0%), but not cognitive change. Associations were found for clinically significant, persistent and intermittent distress. Dementia was associated with distress assessed at ages 65‐75, and 55‐64, but not 45‐54 years.

Findings highlight the relevance of psychological distress in later cognitive outcomes, with potential future implications for dementia prevention and identifying high‐risk groups.

Psychological distress was associated with lower cognitive level in five UK studies.Higher baseline psychological distress was associated with subsequent dementia.Continuous and clinically significant distress were linked with adverse outcomes.Persistent and intermittent distress were associated with poorer cognitive outcomes.Associations were found for distress at ages 55‐64 and 65‐75, but not 45‐54 years.

Psychological distress was associated with lower cognitive level in five UK studies.

Higher baseline psychological distress was associated with subsequent dementia.

Continuous and clinically significant distress were linked with adverse outcomes.

Persistent and intermittent distress were associated with poorer cognitive outcomes.

Associations were found for distress at ages 55‐64 and 65‐75, but not 45‐54 years.