Mental retardation in Swedish urban children: some epidemiological considerations

Tourette syndrome in the general child population: cognitive functioning and self- perception

The aim of the study was to examine the cognitive function and self-perception in a school-population-based sample of children with Tourette syndrome (TS). Many studies have examined cognitive and emotional functioning in clinical samples but to our knowledge, there is no population-based study of TS in schoolchildren. In a population-based sample identified in a rigid diagnostic procedure (n = 25), cognitive functioning and self-perception were examined. There was a large variation in the cognitive functioning of children with TS, at least one third obtaining subnormal results. The profile of index scores on the Wechsler Intelligence Scale for Children (WISC) factors was somewhat uneven, with the freedom from distractibility and processing speed factors presenting the lowest median scores. The TS group had more negative self-perceptions than a comparison group. Tic severity or age at onset was not associated with cognitive performance or self-perception. Children who were taking medication had lower full IQ scores than children who were not. Low cognitive abilities and negative self-perception may be common in community-based samples of children with Tourette syndrome.

ADHD, DAMP and other neurodevelopmental/psychiatric disorders in 6-year-old children: epidemiology and co-morbidity

A total population of 589 6-year-old children were screened for neurodevelopmental/neuropsychiatric disorders by questionnaires to parents and preschool teachers, and by examination of motor abilities at the Child Health Center. Fifty screen-positive and fifty screen-negative children were assigned for complete neuropsychiatric assessment comprising a detailed history, psychiatric and neurodevelopmental assessment, neuropsychological examination and speech/language evaluation. Comprehensive diagnoses were made on the basis of all the available information. In the total population, 63 children (10.7%) with disorders were identified, 10 of whom had a diagnosis established before the study. The prevalence rates for deficits in attention, motor control and perception (DAMP) were 5.3 to 6.9%, for attention deficit hyperactivity disorder (ADHD) they were 2.4 to 4.0% and for mental retardation, 2.5%. Co-morbidity was established for ADHD on the one hand and DAMP, mental retardation and Tourette syndrome on the other. The findings suggest the need for a school entrant screening examination for the types of problems examined in this study.

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 investigated in a Swedish suburban municipality with special demographic characteristics. The study population consisted of the 6397 children aged 9-15 years residing in the municipality on December 31, 1994. A total of 82 children fulfilled psychometric and adaptive criteria of MMR, corresponding to a prevalence of 12.8/1000. The prevalence was higher than that reported in previous Swedish and Finnish studies using similar case-finding methods. This can probably be explained by the lower socioeconomic status in the municipality studied and by the fact that testing is now more acceptable. Nearly 90% of the MMR children had symptoms in their preschool years, mainly motor, speech/language deviations and a relative inability to perform certain tasks. These symptoms also occur in children with minimal brain dysfunction/ deficits in attention, motor control and perception which should be taken into consideration when selecting screening tests.

An epidemiological/genetic study of mental subnormality in Assiut Governorate, Egypt

The aim of this investigation was to study the epidemiologic and genetic aspects of mental subnormality (MS) in Assiut Governorate, representing the Egyptian population. The sample comprised 3000 randomly selected subjects from three localities: one urban (Assiut City) and two adjacent rural villages. Age-matched controls were chosen for comparison. The Stanford-Binet test was administered to each individual. During history-taking special attention was paid to consanguinity and categorization on a genetic basis. The results revealed 116 cases with MS, showing an overall prevalence of 3.9%, which varied in the three locations: 3.4% in Assiut City, and 3.8% and 4.4% in the two rural locations. Clinico-genetic classification revealed the following: idiopathic MS 27.6%, MCA/MR syndromes 24.1%, primary CNS defect 12.9%, Martin-Bell syndrome 10.3%, inborn errors of metabolism 9.5%, tetratogenic and environmental causes 5.2%, MS and epilepsy 4.3%, chromosomal disorders 3.4% and MS associated with psychiatric disorder 2.6%. Parental consanguinity was found in 65% of the total sample, which emphasizes the role played by that factor in the etiology of mental subnormality in Egypt.

An epidemiological study on severe mental retardation among schoolchildren in Bologna, Italy

The prevalence, causal origin of and impairments associated with severe mental retardation (SMR) were investigated among all school-age children (six to 13 years) living in the city of Bologna, Italy. 90 children (57 boys, 33 girls) with IQs less than or equal to 50 were identified. The prevalence of SMR was 4.2 per 1000 for males, 2.5 per 1000 for females and 3.4 per 1000 for both sexes. Causal origin was prenatal for 33.3 per cent, perinatal for 14.4 per cent, combined pre- and perinatal for 5.6 per cent and postnatal for 13.3 per cent. Another 12.3 per cent of the children with IQs less than or equal to 50 had autism or childhood psychosis, while there was no evident cause of mental retardation for the remaining 21.1 per cent. 50 per cent had at least one associated physical or neurological impairment other than mental retardation, with epilepsy and cerebral palsy predominating.

Psychiatric disorders in mildly and severely mentally retarded urban children and adolescents: epidemiological aspects

A total of 149 children aged 13-17 years were examined. 83 were mildly and 66 severely mentally retarded. These children, especially the severely retarded ones, are representative of all mentally retarded children born in 1966-1970 and living in Göteborg, Sweden. 64% of the severely mentally retarded and 57% of the mildly mentally retarded children were suffering from a handicapping psychiatric condition. Autism-like 'psychotic behaviour' was common in the severely retarded. 0.2% of the total child population aged 13-17 years suffering from the combination of mental retardation and 'psychotic behaviour'. Epilepsy was associated with psychiatric abnormality, but Down's syndrome was generally not so associated.

Psychiatric illness among the mentally retarded. A swedish population study

Object--The aim of this investigation was in the first place to study the relation between mental retardation and other mental disturbances. The second aim was to study the frequency of severe and mild mental retardation in an adult Swedish population and to throw some light on the socio-medical situation of the adult mentally retarded. Methods--A primary sample, stratified with respect to population density, was extracted from the population in the age group 20-60 years, resident in Kopparberg County, Sweden, on 1 July 1977. The mildly and severely mentally retarded in this sample were identified. Enquiry was made into the presence of additional handicaps in the mentally retarded. Social conditions including alcohol consumption and the occurrence of abuse and criminality were studied in the two retarded groups and a control group representing the rest of the population. The three groups were compared by rating with the Comprehensive Psychopathological Rating Scale (CPRS), by classification of any mental illness present according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-III) and by determining their intake of psychotropic drugs and anti-epileptics. The mildly mentally retarded and the control group were also compared with respect to neuroticism and extraversion-introversion by rating with the Eysenck Personality Inventory (EPI). Results--The study revealed a prevalence of 0.27% for severe (IQ less than 53) and 0.32% for mild (IQ 53-73.7) mental retardation in the age group 20-60 years. All the severely retarded, but only just over half the mildly retarded, were known to the care authority. The majority of the former were living in some form of institution, whereas this applied to only 15% of the mildly retarded. Nineteen per cent of the severely retarded and 4% of the mildly retarded had manifest epilepsy. Defects of movement and of hearing were most prominent among the mildly retarded, while the frequency of specific speech disturbances was greater among the severely retarded, approximately 10% of whom had no power of verbal communication. Visual defects were recorded in about one-third of both groups. The study showed that alcohol intake was lower among both the severely and mildly mentally retarded than among the persons in the control group and that the frequency of abuse and criminality was as high among persons of higher intelligence as among the mentally retarded. The severely retarded, particularly the men, showed a raised psychiatric morbidity as compared with the mildly retarded and the control group.(ABSTRACT TRUNCATED AT 400 WORDS)