NADD, also known as The National Assocation for the Dually Diagnosed was founded in 1983 as a not-for-profit association.The catalyst for the founding of NADD arose from the need for an open forum to promote and exchange of ideas, principles and concepts concerning individuals who have the co-existence of mental illness and intellectual disabilities. NADD has been growing at a steady rate since its inception. Through the dissemination of cutting edge knowledge, we have been influential in the development of appropriate community based policies, programs and opportuities in addressing the mental health needs of persons with have intellectual disabilities.
NADD had grown rapidly since its founding in 1983 and is now represented in every state in the United States and in Canada, Australia, Japan as well as in Europe. Tennessee is the only state in the United States that has a Chapter of NADD.