[Minimal brain dysfunction--on the revision of a clinical concept. Clinical data of a total pediatric and adolescent psychiatric patient population].

After a discussion of the changes of the MCD concept over the years, the authors describe their own investigation of a total sample of 3280 children, attending outpatient and inpatient facilities of three counties with a total population of 574,000 inhabitants. The aim of the study was to investigate the frequency, sex distribution, and social class dependency of the MCD-diagnosis and its relationship to clinical-psychiatric syndromes. The following results were obtained: There is a strong correlation of MCD-diagnosis with age, sex, and social class. MCD was most frequently diagnosed in the age groups of 3-6, 6-9 and 9-12 years, being twice as frequent in boys than in girls and dominating among the lower social classes. The frequency of MCD in the total sample was 11%, taking into consideration all age-classes. MCD was significantly associated only with two psychiatric syndromes: conduct disorders and hyperkinetic syndrome. There was no correlation with emotional disorders or neurosis, however, a very strong one with specific delays in development, defined according to the multiaxial classification system. 72% of the children diagnosed as MCD-children revealed specific delays in development. But this high correlation was caused only by two conditions: developmental speech/language disorders and specific motor retardation. There was no correlation between MCD and specific reading retardation nor with other specific learning difficulties or mixed developmental disorders. Future research in this field should look upon the so-called MCD more in terms of general developmental delays than in terms of brain pathology.