A common misconception about ADHD is that it causes an impairment with intelligence. This could not be further from the truth. Some ADHDers, myself included, have been told, “You can’t have ADHD; you’re so smart.” The fact of the matter is many people with ADHD are incredibly intelligent. ADHD does not influence one’s intelligence. However, those who are intelligent and have ADHD often go undiagnosed for years.