Intelligence and functional somatic symptoms and syndromes

PhD ceremony: Ms. E.M. Kingma, 16.15 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Intelligence and functional somatic symptoms and syndromes

Promotor(s): prof. J.G.M. Rosmalen, prof. J. Ormel, prof. P. de Jonge

Faculty: Medical Sciences

Functional somatic symptoms (FSS) cannot be conclusively explained in terms of conventionally defined organic pathology. The still poorly understood etiology urges the need for research on factors that are associated with the development of FSS. We hypothesized that one of the factors contributing to the etiology of FSS might be low intelligence. Lower intelligence predicted FSS over the life course and in different types of populations, indicating a robust relationship between lower intelligence and FSS. Thus, people with lower intelligence have on average higher numbers of FSS than people with higher intelligence.

Different pathways for the link between intelligence and FSS were studied. Plausible pathways indicate a role for low socioeconomic status and psychosocial stress, but the nature of these pathways seems to differ over the life course. In early life, adolescents with lower intelligence are especially at risk for FSS when perceived academic expectations are high. However, this effect from high academic expectations does not seem to extend into adulthood. In adulthood, an unfavorable work situation might be a possible mediator in the association between intelligence and FSS. Adults with lower intelligence are more often unwillingly unemployed, which could predispose them to develop FSS. The role of intelligence in health deserves further study, especially with regard to the mechanisms responsible for the association between intelligence and FSS.