Intellectual Disability

This chapter presents an overview of intellectual disability (ID), a neurodevelopmental disorder that impacts intellectual and adaptive functioning across the lifespan (Anderson et al. Intellect Dev Disabil. 57:421–38, 2019). In the United States, approximately 1% of the population is affected by ID although prevalence estimates vary widely and predominantly focus on children. Individuals with ID require varying levels of support across conceptual (e.g., problem-solving, academic skills, and memory), social (e.g., social decision-making and perspective-taking), and practical (e.g., personal care and leisure skills) domains to promote community engagement, quality of life, safety, and independence. In addition to providing a broad introduction to ID, this chapter aims to synthesize and summarize recent work on co-occurring psychiatric and medical conditions, assessment practices, and psychosocial and pharmacological interventions.