There’s been a new look at the long-term health impacts of ADHD.

The new study from Henry Ford Health says people with ADHD have a significantly shorter life expectancy. According to Henry Ford’s researchers, women with ADHD may lose up to nine years, and men up to seven years.

Henry Ford Health psychiatrist Dr. Lisa McLean was asked why ADHD is often misdiagnosed.

“One of the core symptoms of ADHD is problems with focus and concentration, which can also occur in other psychiatric diagnoses, like a person suffering with anxiety or a person also struggling with depression,” McClean said.

15.5 million Americans have ADHD. The most misdiagnosis is among women and girls.