The group of mental disorders discussed here have behavioral characteristics that were once thought to be very different from one another but are now considered similar because of their repetitious nature that usually involves movement.

Tic Disorder should be included in this group and has been discussed in a previous article that can be reviewed at www.AbleDev.Com in the resource room. A note of interest is that Tic Disorder is frequently seen in individuals with Obsessive Compulsive Disorder. The latter will be discussed here along with stereotypical movements often noted in individuals with Pervasive Developmental Disorder, Stereotypic Movement Disorder and Trichotillomania.

A stereotypy is generally regarded as a rhythmical, repetitive, socially unacceptable and purposeless movement or senseless vocalization. The activity is deliberate to the point of being "driven".

The diagnosis of Stereotypic Movement Disorder is made when an affected individual who, because of the activity, is considerably limited in performing useful activities or sustains significant self-injury. This disorder is usually diagnosed in children with Neurodevelopmental Retardation. The activities, to name just a few, include self-punching and biting, head and facial butting, eye poking or continuous screaming.

Less problematic stereotypies occur in children who are on medication, who have other mental conditions and in some who are apparently otherwise normal. The repetitive activities are usually confined to simple self picking, pinching, stroking or lightly striking and do not necessitate a diagnosis in and of themselves. Simple rocking or head bumping in infancy and early childhood is usually transient and is presently deemed inconsequential. Unless there are issues with injury, productivity or social demeanor the stereotypies should be considered symptoms associated with other specific disorders or be considered within the limits of normal behavior.

The repetitive movements or stereotypies seen in Pervasive Developmental Disorder (PDD) also known as Autistic Spectrum Disorders are extremely interesting repetitive movements. Usually the movements are rhythmical, purposeless and may be complex, ritualistic and sometimes multiple and/or sequential. Simple hand flapping may be the only movement an affected child might have while another child may engage in using one or more objects in a purposeless, repetitive activity. Repetitive vocalizations including echolalia (repeating what is said to the affected individual) are also a characteristic of PDD. A fairly complex example would be the autistically disordered child who turns the pages of a book over and over while watching the process in a mirror. These activities do not usually cause distress in the affected child but often cause a serious social stigma in those who are considered intellectually adequate.

Repetitive activities seen in Obsessive-Compulsive Disorder (OCD) are by definition compulsive in nature and are performed to relieve anxiety-provoking thoughts (obsessions). In many instances Compulsions involve a higher order of brain function. For example, repetitive hand washing because of the fear of becoming contaminated with germs.

Children with OCD count, check or organize their surroundings over and over again. They are often unaware that their behaviors are the result of obsessions. OCD should be diagnosed only when there is significant social or academic dysfunction.

Trichotillomania is a repetitive disorder where a child will pull out scalp hair until there are readily noticeable bald spots. The child often shows little concern about this and may actually bring the hair to an adult.

One can see the behavior and activity in all of these disorders are internalized and repetitive, at times difficult to separate from one disorder to the next. Because of this some experts believe the disorders have a common neurobiologic link and therefore might benefit by the same psychotherapeutic agent.

So far, OCD and Tic Disorders have responded favorably to a common drug group termed selective serotonin reuptake inhibitors (SSRIs). However, the use of these agents in Stereotypic Movement Disorder and Pervasive Developmental Disorder has been less rewarding but perhaps worth a trial in selected individuals. Trichotillomania is more difficult to treat but some experts believe antidepressants including SSRIs are worth a trial. For more information about these and other disorders, see the glossary at

Author's Bio: 

Dr. Deane G. Baldwin, M.D., FAAP, is a Board Certified Pediatrician in private practice for 39 years. Specializing in developmental disorders and school health. For more information go to www.ABLEDEV.COM