Many factors are associated with problem behaviors in people with developmental disabilities:

• neuroanatomic, physiologic, and chemical abnormalities
• deficits in executive functioning and inhibitory control
• deficits in communication
• impoverished living conditions
• learning experiences

These factors can be grouped into two broad categories:

• processes that are internal to an individual
• processes associated with the external environment

The reasons for the emergence of any particular behavior can be very complex. To understand the origins of problem behaviors and their intended purposes well enough to create a successful plan of intervention, data must be collected very carefully, beginning with a precise, objective description of exactly what is happening. This characterization is of primary importance. It should not only describe the behavior but also should indicate where the behavior occurred, its precipitating factors, and its consequences for the individual.

The cases presented on the following pages are, of course, not all-inclusive.

Internal causes of problem behaviors:

• Cognitive deficits
• Psychiatric problems
• Pain and sensory difficulties
• Lesch-Nyhan syndrome and Riley-Day syndrome
• Endorphin and serotonin models
• Seizures
• Medication side effects

External causes of problem behaviors

• Social conditions
• Environmental conditions

Adapted from: Sudhalter V. Problem behaviors in individuals with developmental disabilities. In: Devinsky O and Westbrook LE, eds. Epilepsy and Developmental Disabilities. Boston: Butterworth-Heinemann; 2001;165–174.
With permission from Elsevier (www.elsevier.com).
Reviewed and revised May 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.