Most intellectual and developmental disabilities (IDDs) are now treatable but incurable. That is, current treatments can help individuals with IDDs in important ways but seldom eradicate the disability. For example, two treatments with solid scientific support are applied behavior analysis (ABA) and psychotropic medication. With ABA interventions, many individuals with IDDs learn skills they would not otherwise be able to master. These skills enable them to communicate, interact with others, take care of themselves, engage in leisure activities, and work at school or in a job. Still, the majority of individuals who receive ABA continue to have significant overall delays in these areas. Medications sometimes reduce behavior problems such as aggression, insistence on routines, and difficulty falling or staying asleep, but they seldom eliminate such problems. Beyond limited effectiveness, these treatments have other drawbacks. ABA is labor intensive, often involving many hours per week of intervention for years; medications are prone to unpleasant side effects and usually work only as long as the individual keeps taking them. Both ABA and medications require supervision by highly trained professionals.