Background: Neuroticism and somatic complaints are linked, and the aim of this study is to disentangle which mechanisms may be responsible for this association.
Method: In a stratified sample of 7076 adults (18-65 years), neuroticism, 22 self-reported chronic somatic conditions and five broad CIDI-diagnosed psychiatric syndromes were assessed at baseline and, in 3625 (51%) subjects, 3 years later. Using path analysis we examined whether neuroticism has direct links with future somatic morbidity and, conversely, whether morbidity at baseline is linked with higher neuroticism later on.
Results: Neuroticism at baseline is associated with psychiatric and somatic morbidity at follow-up after 3 years (31% and 24%, respectively, are direct associations, i.e. unmediated by each other or neuroticism at follow-up and independent of morbidity at baseline). Conversely, somatic and psychiatric morbidity at baseline are associated with increased neuroticism at follow-up (27% and 15%, respectively, are direct associations).
Conclusions: Neuroticism raises risk for psychiatric and somatic morbidity but also results from them. It represents a central nexus in the process of morbidity accumulation.