ADHD News & Research

Increased Dementia Risk in Adults with ADHD

Adults with ADHD were more than three times as likely to develop dementia in their later years than counterparts without ADHD, although the link between the two disorders remains unclear.

July 10, 2017

A mid-size Taiwanese study, published in June in the Journal of Attention Disorders, showed that adults with ADHD are more prone to developing dementia later in life. The study relied on data from Taiwan’s National Health Insurance Research Database, which includes more than 99 percent of the population. Rather than look at the entire population, researchers focused on 675 adults between the ages of 18 and 54 who were diagnosed with ADHD in the year 2000, as well more than 2,000 gender- and age-matched control subjects without ADHD.

According to insurance claims over a 10-year period, the adults with ADHD were 3.4 times more likely to develop dementia than the control subjects, the study found. This association remained after the researchers controlled for age, gender, comorbid diagnoses, and income levels. The results sync up with a 2011 study that found that adults with a certain type of dementia were likely to have had ADHD symptoms earlier in life, and support the link between ADHD and other brain-based disorders.

The reason for the specific link between ADHD and dementia “remains unclear,” the researchers wrote, and the current study was not without limitations. Since the information came solely from insurance claims, for instance, it was impossible to control for family history, education levels, or other factors that may have contributed to the development of dementia. On top of that, the subjects weren’t diagnosed with ADHD using uniform methods, the researchers wrote, meaning some of the control group might have had undiagnosed ADHD, and vice versa.

Despite these limitations, however, the link between ADHD and dementia is concerning, and warrants further investigation, the researchers said. They recommend that more studies be done — particularly ones that use larger nationwide data sets.