The association between arthritis and psychiatric disorders; results from a longitudinal population-based study.

BACKGROUND

To disentangle cross-sectionally and longitudinally the relationship between arthritis and psychiatric disorders, and to examine the relationship between age and incidence of (1) any psychiatric disorder among respondents with and without arthritis and (2) arthritis among respondents with and without any psychiatric disorder.

METHODS

Data are from the Netherlands Mental Health Survey and Incidence Study (NEMESIS), a nationally representative household survey with repeated measurements in 1996, 1997 and 1999. Self-report was used to ascertain arthritis. Psychiatric and substance use disorders were diagnosed with the WHO Composite International Diagnostic Interview.

RESULTS

Regarding the cross-sectional results, it was found that the strength of the association of arthritis with mood and anxiety disorders was similar [odds ratio (OR)=1.48, 95% confidence interval (CI)=1.09-1.99 and OR=1.42, 95% CI=1.11-1.81, respectively]. The longitudinal results showed that preexisting arthritis elevated the risk of developing any mood disorder (OR=1.94, 95% CI=1.23-3.07), whereas having any mood or any anxiety disorder did not predict new-onset arthritis. The incidence of any psychiatric disorder was significantly higher among younger persons (<45 years) with arthritis, compared to others in the same age category without arthritis.

CONCLUSIONS

Arthritis is associated with psychiatric disorders. The temporal relationship points to one direction: arthritis predicts new onset of psychiatric disorder (mood disorder) instead of the reverse. Especially younger people (<45 years) with arthritis are at risk of developing a psychiatric disorder. Screening and simultaneous treatment of comorbid mood disorder and arthritis are recommended as part of routine in primary care.