[Children with mild mental retardation in the special schools. "Top of the iceberg"?].

Mild mental retardation (MMR), in UK learning disabilities, is defined as an IQ in the interval between 50-70 in combination with defined adaptive criteria (ICD-10 and DSM-IV). We have analysed the prevalence, the functional assessments, associated impairments and medical aspects of the children who attended grade 1-9 in the special schools for children with mild mental retardation in the northern part of Stockholm in 2001. The prevalence was 0.4%. We assume that this prevalence represents the "top of the ice-berg", i.e., comprising those with IQ's in the lower IQ interval (IQ 50-60), since 63% of the children in this MMR-group had been diagnosed already at the time of school-start or the 3 first years at school, 76% had been medically assessed and 45% had at least one additional neuroimpairment. The "true" prevalence of MMR in this age-group is not known. Our conclusion is that we have probably identified less than half of the total group with MMR and that the unidentified group--"those who are under the surface" run the risk of never having their cognitive dysfunctions identified. MMR has wide implications for the individual in today's society. That means that there is a need of clear guidelines for diagnosis and assessments. With such guidelines and with increasing knowledge and acceptance in the society, more children and families will be offered appropriate measures and support.