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Mental Health Conditions & Developmental Disabilities

NCJ Number
Date Published
April 2022
2 pages

This document lays out the differences between mental health conditions and developmental disabilities, explaining why it is important to know the difference and common behaviors and characteristics of each.


This brief, informational document presents an explanation of the differences between mental health conditions, also known as mental illnesses, and developmental disabilities.  The document defines the two: a mental health condition can affect mood, thinking, and/or behavior; and a developmental disability is a physical and/or mental impairment that begins before age 22, is likely to continue indefinitely, and results in functional limitations in either one or several abilities such as self-care, walking/moving around, self-direction, independent living, economic self-sufficiency, or language. The document provides the various categories of mental health conditions and developmental disabilities; it highlights common characteristics and behaviors that may be observed with each, and emphasizes the differences between the conditions and how treatment varies depending on a person’s affliction.

Date Published: April 1, 2022