Project 460431

Approximately 3-4% of adults over the age of 50 suffer from symptoms of attention-deficit/hyperactivity disorder (ADHD). Often, these symptoms present as cognitive deficits such as executive dysfunction (e.g., distractibility) or memory impairments (e.g., forgetfulness) but these can be mistaken for signs of early neurodegenerative disease. Research from the past 15 years suggests there may be a possible link between ADHD and neurodegenerative disease, specifically Lewy body diseases (LBD) which include Parkinson's disease, Parkinson's disease dementia, and dementia with Lewy bodies. Studies suggest that older adults with ADHD may have higher chance of developing dementia than those without ADHD, and people with LBD report having ADHD symptoms early in life. However, only a few of these studies have considered other factors that may affect or mediate the relationship between ADHD and risk of neurodegeneration. One such factor is cerebrovascular disease, (e.g., diabetes, smoking habits, obesity, and high blood pressure), which has been linked to cognitive decline in older adults. People with ADHD also have a higher risk of developing these cerebrovascular factors throughout their lifetime. The purpose of the proposed research is to use healthcare data to examine whether the potential increased risk of cognitive decline and neurodegeneration for people with ADHD may be due, in part, to cerebrovascular disease. This project aligns with the CIHR SPA 2022 topic of Neurodegenerative and Cerebrovascular Diseases because it explores ADHD as an underlying risk factor for LBD and whether this may be mediated by cerebrovascular disease.