Obsessive Compulsive Symptoms in Developmentally Disabled Individuals
Obsessions, compulsions and rituals are frequently associated with intellectual or developmental disabilities (IDD) and autism. The obsessive compulsive behaviors occur at high rates among persons of all ages with developmental disabilities. In addition, IDD and autism frequently overlap, and the overlap is associated with an even greater risk for developing obsessions and compulsions.
Although OCD appears to be rare in persons with IDD (3.5%), obsessive, compulsive, and ritualistic symptoms are common. High rates of obsessive compulsive behaviors have been consistently reported in individuals with Prader-Willi Syndrome, and Down Syndrome has been associated with the unique form of OCD characterized as obsessional slowness (i.e., individuals spend several hours each day performing tasks of daily living which should be completed much quicker).
A potential link between sensory hypersensitivity and the use of excessive rituals may underlie these behaviors. Sensory processing refers to the way in which the nervous system manages incoming sensory information. Sensory dysfunction in a child is likely to be experienced as psychologically distressing and upsetting. Consequentially, the child may search for ways to calm themselves and thereby develop excessive ritualistic behavior. These ritualistic behaviors may also include OC-related activities such as hair pulling or compulsive skin picking, for which the clinician should assess.
Further, intellectual or developmental disabilities in obsessive compulsive related disorders, such as Trichotillomania, skin picking, and Tourette’s Disorder or tics, can present challenges in diagnosis and treatment. These disorders are quite common in the mentally handicapped population as well. A study of 259 patients with mental retardation found that 5% exhibited symptoms of Trichotillomania and 16.6% had some form of motor and/or vocal tic. Further, skin picking is very commonly found in Prader-Willi syndrome (e.g., from 82% to 95% of clinical samples have been found to have significant skin picking), a neurodevelopmental disorder resulting in intellectual disabilities resultant from an abnormality at chromosome 15.