Intellectual Disability

Individuals with an intellectual disability are one of the most underserved populations in the United States. They have higher rates of medical and psychiatric comorbidity when compared to the general population and face considerable healthcare disparity. Challenging behavior such as physical or verbal aggression is the most common reason why this population interfaces with the mental healthcare system. Understanding and correctly diagnosing the underlying etiology of challenging behaviors requires comprehensive evaluations along with awareness of the key variables that contribute to the occurrence of these behaviors. The differential diagnosis of challenging behavior is wide and includes mental illness, medical illness, pain, side effects from medications, behavioral phenotype of underlying syndrome, behavioral/functional, deficit of skills, and/or developmentally appropriate behavior.  This review contains 1 figure, 6 tables and 83 references Key words: behavioral phenotype, challenging behaviors, etiology, intellectual disability, mental retardation, mental illness, psychiatric disorders