The Attention Deficit Disorder Association (ADDA) is the world's leading nonprofit organization dedicated exclusively to adult ADHD. Founded over thirty years ago, ADDA has grown into the primary source of information, resources, and connection for adults living with ADHD and the people who support them. As a proud member of the World Federation of ADHD, the organization brings together scientific research and lived experience to build understanding and connection worldwide.

ADDA focuses its work on the moments where adults with ADHD struggle most, from everyday life to the workplace. It runs virtual support groups, educational webinars, and workplace toolkits for managers and HR professionals, and hosts the International ADHD Conference, the largest event of its kind, alongside a monthly newsletter and support for research into adult ADHD.