Dementia is one of the leading causes of death globally and increasing longevity ensures its prevalence will rise even further. As there is no known treatment that slows down the progression of this disorder, there is an emphasis to focus on cognitively healthy individuals at risk of developing dementia as the best strategy to reduce dementia incidence and prevalence. Identifying risk factors and biomarkers for dementia is increasingly important. Alcohol use and working memory have been shown to be associated with dementia, however the nature of these associations are unclear. This research project aims to use a number of methodologies novel to the field of dementia by using combination of observational and genetic techniques. This approach is essential for testing whether there are critical or sensitive periods for dementia risk and may help to uncover whether alcohol use and/or working memory performance contribute to dementia. Identifying early modifiable risk factors for dementia has the potential to gain a greater understanding of dementia progression and inform preventative interventions.