Kathleen Nadeau, Ph.D., is the founder and clinical director of the Chesapeake ADHD Center of Maryland, Learning and Behavioral Health, one of the largest and oldest ADHD specialty clinics in the US. She is a psychologist who has practiced for over thirty years, specializing in the diagnosis and treatment of ADHD.

Dr. Nadeau is a prolific writer about ADHD, and has authored or co-authored over a dozen books on the topic. She and her long-time professional collaborator, Patricia Quinn, M.D., shared the CHADD Hall of Fame Award in 1999 for their groundbreaking work on women and girls with ADHD.

She has served on the professional advisory boards of both CHADD and ADDA. She is the co-founder of the National Center for Gender Issues in ADHD, a non-profit organization dedicated to serving the needs of girls and women with ADHD. Dr. Nadeau has appeared on the Today Show and the Morning Show, as well as on numerous radio programs is a frequent lecturer both in the US and abroad on topics related to ADHD. She is currently working on a book focused on the needs of older adults with ADHD, to be titled Still Distracted After All These Years.