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Mental Retardation and Mental Illness

It’s one of my pet peeves. “He’s having behaviors,” says the new teacher. Argh! I hate that phrase. Of course he’s “having behaviors.” We all have behaviors. When we stop having behaviors, we’re dead. What she means, of course, is that her student is behaving in ways that are difficult, challenging, and unacceptable to her. She wants a behavior plan. She wants to get rid of the difficult behaviors. I want more information. Can we talk?

I think it’s a holdover from the old days. As recently as only thirty years ago, many people in the field thought that people with mental retardation could not have a mental illness. Some people even thought that people with mental retardation didn’t have feelings like the rest of us, or didn’t want to relate to other people, or were too “retarded” to make sense of things.

It’s interesting and humbling to realize that when people are convinced that something is true, they often don’t get confused even by their own observations. Looking through the lens of “he’s retarded,” good-hearted people just didn’t recognize that the people in their families or in their care do feel, think, make sense of things, and, sometimes, are overwhelmed by their feelings and by their situations. Looking through the lens of mental retardation, these well-intended people didn’t consider that cognitively disabled people can have the same biochemical imbalances that cause various mental disorders from depression to schizophrenia. Looking through the lens of mental retardation, these good-hearted people didn’t know that they could help mitigate the cause of the distress by treating it in the same way as they would any other person having a hard time. Instead, they tried to control it.

Current Thinking on Behavior Change

But those were the old days. Behavior change is now recognized as an important clue that something is going on. Experienced caregivers observe, keep careful data, and analyze. Yes, sometimes behavior is a bid for attention, or a way to avoid a task, or a temporary expression of frustration. In those cases, a behavior plan can be very helpful.

But behavior change also can indicate something more serious. Perhaps the person is physically ill. Over 80 percent of psychiatric admissions for people with retardation lead to the discovery of an undiagnosed and untreated medical condition. The most common are urinary tract infections and constipation.

Maybe she or he is reacting to a medicine. Non-psychiatric medicines can produce psychiatric problems which in turn can cause behavior change. For people over age 50 (age 40 for people with Down Syndrome), it can be an indicator of emerging dementia. Or maybe it’s a signal that there is an emerging mental illness. Depending on the study, it is now estimated that 30 to 80 percent of people with mental retardation also have mental health issues. Modern psychiatry and psychological practice recognize that people with retardation suffer from the full range of psychopathology as everyone else, from anxiety and depression to psychosis.

In any of the above situations, a behavior plan not only won’t help, but will either mask or exacerbate the problem. Good analysis leads to a good diagnosis which then informs treatment. And good treatment often then leads to reduction or elimination of behaviors that trouble others.

Mental Retardation and Mental Illness

Marie Hartwell-Walker, Ed.D.

Marie Hartwell-WalkerDr. Marie Hartwell-Walker is licensed as both a psychologist and marriage and family counselor. She specializes in couples and family therapy and parent education. She writes regularly for Psych Central as well as Psych Central's Ask the Therapist feature. She is author of the insightful parenting e-book, Tending the Family Heart.

Check out her book, Unlocking the Secrets of Self-Esteem.

APA Reference
Hartwell-Walker, M. (2020). Mental Retardation and Mental Illness. Psych Central. Retrieved on August 5, 2020, from
Scientifically Reviewed
Last updated: 17 Jan 2020 (Originally: 17 May 2016)
Last reviewed: By a member of our scientific advisory board on 17 Jan 2020
Published on Psych All rights reserved.