NADD is an international association for persons with intellectual/developmental disabilities and mental health needs, comprised of individuals, families, and support professionals dedicated to enhancing the understanding and treatment of people experiencing co-occurring intellectual/developmental diagnoses (IDD) and mental health conditions or mental illness (MI).



To promote leadership in the expansion of knowledge, training, policy, and advocacy for mental health practices that promote a quality of life for indviduals with dual diagnosis (IDD/MI) in their communities.


Members are the fabric of the NADD community, and your participation is vital to the fulfillment of our mission!

Members enjoy a multitude of benefits that promote the most contemporary theories, approaches and treatment methodologies for people with dual diagnosis. 

Memberships are available at the corporate and individual levels, and all Members have access to the most innovative research and training in intellectual/developmental disabilities and mental health conditions – including research on assessment, diagnosis, psychopharmacology, therapy, program models, staff training, social determinants of health, and other aspects of mental wellness.  

NADD members are connected to an extensive international network of like-minded professionals dedicated to advancing the mental wellness of people with intellectual disabilities.