The distribution of psychiatric and somatic ill health: Associations with personality and socioeconomic status

Objective: Psychiatric and somatic disorders frequently co-occur in the sam e individuals. We examined whether this happens because these types of morb idity share risk factors or because they are risk factors for each other. M ethods: Negative binomial regression was used to examine, in a random sampl e of Dutch adults (N = 7076), cross-sectional associations of sociodemograp hic and personality variables like income and neuroticism with the presence , over 1 year, of 30 somatic and 13 psychiatric disorders, with the latter diagnosed by structured interview. We examined to what extent the links of these variables with these two morbidity types were independent of each oth er. Results: This population experienced 5050 somatic and 2438 psychiatric disorders during the preceding year. Subjects reporting more somatic disord ers had more psychiatric disorders. Neuroticism, followed closely by low ed ucational attainment, was the strongest correlate of both morbidity types. After adjustment for all other covariates including somatic morbidity, the number of psychiatric diagnoses rose 1.84-fold (95% confidence interval = 1 .74-1.94) per standard deviation increase in neuroticism. Likewise, adjuste d for all other covariates including psychiatric diagnoses, 1.42 (95% confi dence interval = 1.35-1.50) times more somatic disorders were reported per standard deviation increase in neuroticism. Conclusions: Personal features like neuroticism and low educational attainment are linked with psychiatric and with somatic morbidity. These links are largely independent. Although this study was cross-sectional, the results suggest that these different ty pes of morbidity may have overlapping etiologies.