[Relation of intelligence and the pathogenesis of various psychological disorders in children]

In a study on 5- to 13-year-old children referred to a residential facility for psychiatric care we explored the interrelations between intelligence on the one hand and onset of manifest behavior problems and clinical diagnosis on the other. We controlled statistically for confounding effects of parental occupational status and the children's sex. There was a statistically significant association between type of disorder and level of intelligence. When intelligence was above average, neurotic and emotional disturbances as well as some other syndromes that are generally considered to have a good prognosis dominated. In contrast, average or below-average intelligence frequently coincided with more enduring types of syndromes such as conduct disorders. The level of correlation between age at onset and IQ depended on the type of disorder. For the children with neurotic/emotional syndromes or conduct disorders, the lower the IQ the earlier the age of onset and initial referral. But this did not hold for children with autism, hyperactivity or certain developmental disorders. The results are tentatively interpreted as supporting the position that cognitive competence acts as a protective factor in emotional development.