الفهرس 
Review of LiteratureOnly 14 pages are availabe for public view
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Abstract
Maladaptive behaviors in the mentally retarded have been reported to be very common and frequent. Their overall prevalence among several studies ranged between 20% and over 60%, with a tendency to increase with the severity of mental retardation. Each item of the behavioural disturbances was variably affected by different characteristics of the retarded people. Also, several aetiological factors have been suggested, such as psychiatric disorders, medical conditions, side effects of medications, biological factors, environmental factors, sleep problems and behavioral aetiologies. Severe behavioural problems can lead to several undesirable personal and social consequences. These relate strongly to parenting stress and burden, and cause residential placement (institutionalization) in many cases. Some of these behavioural disturbances are persistent and long-standing.