How are Developmental Disabilities Diagnosed?

 Developmental disabilities are diagnosed by looking at two main things:

  • The ability of a person’s brain to learn, think, solve problems, and make sense of the world(called IQ or intellectual functioning); and
  • Whether the person has the skills he or she needs to live independently (called adaptive behavior or adaptive functioning).

Intellectual functioning is usually measured by a test called an IQ test.  The average score is 100.  People scoring below 70 to 75 are thought to have developmental disabilities.  To measure adaptive behavior, professionals look at what a child can do in comparison to other children of his or her age.  Certain skills are important to adaptive behavior.  These are:

  • Daily living skills, such as getting dressed, going to the bathroom, and feeding one’s self;
  • Communication skills, such as understanding what is said and being able to answer;
  • Social skills with peers, family members, adults, and others.

To diagnose developmental disabilities, professionals look at the person’s mental abilities (IQ) and his or her adaptive skills.  Both of these are highlighted in the definition of developmental disabilities provided between the lines below.  This definition comes form the Individuals with Disabilities Education Act ( IDEA),  The IDEA is the federal law that guides how schools provide early intervention and special education and related services to children with disabilities.

Providing services to help individuals with developmental disabilities has led to a new understanding of how we define persons with speical needs.  After the initial diagnosis is made, we look at a person’s strengths and weaknesses.  We also look at how much support or help the person needs to get along at home, in school, and in the community.  This approach gives a realistic picture of each individual.  It also recognizes that the “picture” can change.  As the person grows and learns, his or her ability to get along in the world grows as well.