MILD MENTAL-RETARDATION IN SCHOOLCHILDREN IN A SWEDISH SUBURBAN MUNICIPALITY - PREVALENCE AND DIAGNOSTIC ASPECTS

The prevalence of mild mental retardation (MMR)(IQ 50-72) was investig ated in a Swedish suburban municipality with special demographic chara cteristics. The study population consisted of the 6397 children aged 9 -15 years residing in the municipality on December 31, 1994. A total o f 82 children fulfilled psychometric and adaptive criteria of MMR, cor responding to a prevalence of 12.8/1000. The prevalence was higher tha n that reported in previous Swedish and Finnish studies using similar case-finding methods. This call probably be explained by the lower soc ioeconomic status in the municipality studied and by the fact that the testing is now more acceptable. Nearly 90% of the MMR children had sy mptoms in their preschool years, mainly motor, speech/language deviati ons and a relative inability to perform certain tasks. These symptoms also occur in children with minimal brain dysfunction/deficits in atte ntion, motor control and perception which should be taken into conside ration when selecting screening tests.