ADHD Myths & Facts

ADHD and IQ: The Effect of Attention Deficit and Hyperactivity on Intelligence

Studies show that adults and children with ADHD often have high intelligence quotients (IQs), but they face challenges in school or life. Why?

The common wisdom used to be that if you have ADHD, you’re not smart, and if you are smart, you can’t have ADHD. Nonsense. I did a study of 157 adults — all of them fully met diagnostic criteria for ADHD, and all had significant impairment in working memory and processing speed — but they each had intelligence quotients (IQs) of 120 or above, or would fall into the top nine percent of the population.

[Quiz: Can You Distinguish Between ADHD and Learning Disabilities?]

Many of these people had late diagnoses and weren’t recognized as having ADHD problems until they were adults. They suffered a lot and often had difficulties in school before they received adequate treatment. All of them were demoralized and had given up. If they had been diagnosed earlier or had been in an environment where they were supported for their strengths and helped to recognize their limitations — not given a lot of phony happy-talk — their self-esteem would increase. Many people get put down so often that they develop defenses to protect themselves. Early diagnosis and treatment can mean so much in the arc of a person’s life.