There are Harvard professors with the condition, as well as stockbrokers, firefighters, housewives, shop clerks, business owners, writers, and artists. Being smart can help people with ADHD perform better but having ADHD says nothing about someone’s intellectual capabilities. Through a genetic fluke or cosmic joke, people with ADHD often have other diagnosable conditions as well, such as learning disabilities, depression, or addiction problems. It’s as if whatever happens to give the brain attention challenges also strikes elsewhere to create more trouble.