After skimming the article, it seems like they are suggesting a connection between some established/known trends that makes it easier for a person with ADHD to develop dementia.

Known:

- Dementia has many lifestyle risk factors (poor education, hypertension, obesity, hearing loss, depression, diabetes, physical inactivity, smoking, drinking, social isolation)

- ADHD can make it easy to have certain lifestyles (addictions to drugs or food, trouble maintaining relationships, emotional dysregulation, poor education, poor work performance, high risk behavior)

New connection:

- There is significant overlap in the two