The impact of social position on biological ageing through the psychological risk factors of dementia: A Biopsychosocial model of dementia risk

The proposed PhD research aims to explore the relationship between psychological risk factors (such as depression, anxiety, and stress) and biological aging in the context of dementia risk, focusing particularly on high-risk groups like women, people from low socio-economic backgrounds, and Black communities. The research will apply a biopsychosocial model of dementia risk, investigating whether social position (e.g., race, ethnicity, gender, socio-economic status) moderates this relationship.

Key Objectives:
1. Objective 1: Conduct a systematic review to examine the relationship between psychological risk factors for dementia and biological age, identifying the most sensitive biological age metrics.
2. Objective 2: Investigate whether race, gender, and socio-economic status are associated with biological age and if they moderate the relationship between psychological risk factors and biological aging using data from the UK Biobank.
3. Objective 3: Explore whether the relationship between psychological risk factors and biological age differs depending on whether the psychological factors occur in midlife or late life, with moderation by gender and socio-economic status using data from INSIGHT 46.
4. Objective 4: Examine if race or ethnic minority status moderates the relationship between psychological risk factors and biological aging in a Black-majority cohort from South Africa, using data from the HAALSI study.

Methodology:
This project will rely on secondary data from large population-based cohort studies such as UK Biobank, INSIGHT 46, and HAALSI so no ethical approval is required. Various measures of biological age, including telomere length, epigenetic clocks, and brain age, will be assessed alongside psychological factors. The project includes a life-course perspective and intends to use advanced statistical models to explore interactions between social factors and biological aging.

Impact:
This research will contribute to understanding how social and psychological factors accelerate biological aging and increase dementia risk, particularly in disadvantaged groups. By addressing these gaps, the study aims to inform dementia prevention strategies targeted at vulnerable populations.