Objectives To examine the association between psychological distress and dementia diagnosis. Design Matched case-control study. Setting UK primary care practices contributing to the Clinical Practice Datalink GOLD from January 1995 to June 2021.Participants8,015 people aged ≥65 with a diagnosis of dementia and 31,744 matched controls8without dementia, matched on age, sex, GP practice (as a proxy for socioeconomic status) and calendar time using incident density sampling. Primary and secondary outcome measures Associations between dementia diagnosis and number of psychological distress codes, including (i) total codes and (ii) number of unique codes recorded, across four time windows before the index date (0–5, 5–10, 10–15, and 15–20 years). We also examined associations by type of distress, including analyses of the timing of the first recorded code in each distress category. Results Greater number and diversity of psychological distress codes were associated with increased odds of dementia. Associations were strongest in the 0–5 years before index(adjusted odds ratio [a OR] for unique codes: 1.61, 95% CI 1.56 to 1.67; total codes: 1.20,95% CI 1.18 to 1.22) but remained statistically significant up to 15–20 years before diagnosis. In secondary analyses, all psychological distress categories were significantly associated with dementia when first recorded 0–5 years before diagnosis. The highest a ORs in this window were for psychotic symptoms and severe mental illness (4.68, 95%CI 3.15 to 6.97), emotional dysregulation and self-injury (2.90, 95% CI 2.25 to 3.59), and low mood (2.89, 95% CI 2.67 to 3.12). All categories were also significantly associated with dementia in at least one other time window; anxiety and low mood were significant across all four, including 15–20 years prior to diagnosis. Conclusions Psychological distress, particularly when diverse in presentation or emerging closer to diagnosis, was associated with increased odds of dementia up to 20 years in advance. These findings suggest that subclinical and diagnostically heterogeneous symptoms may hold clinical value as early risk signals and support the importance of recognising psychological symptoms, including at subclinical levels, in mid to later life as possible early markers of neurodegenerative change. Earlier recognition and support may contribute to targeted prevention efforts.
Doctorate in Clinical Psychology: Main Portfolio: 1) Eye movement desensitisation and reprocessing for post-traumatic stress disorder for people with acquired cognitive impairment: A scoping review; 2) Is a self-help leaflet a useful and acceptable resource for parents of children born with oesophageal atresia?; 3) Investigating the association between psychological distress and dementia: A retrospective longitudinal analysis of case-control data.
Bailey, E. (Author). 10 Sept 2025
Student thesis: Doctoral Thesis › Doctor of Clinical Psychology (DClinPsy)