Incidence of Multiple Psychiatric Disorders Evaluated in Rheumatoid Arthritis

The incidence and prevalence of depression, anxiety disorder, and bipolar disorder are elevated in the rheumatoid arthritis (RA) population as compared with the general population, according to the results of a study published in Arthritis Care Research.

Study researchers used population-based administrative health data from Manitoba, Canada, to identify individuals with incident RA between 1989 and 2012, as well as a cohort from the general population matched 5:1 by year of birth, sex, and region. They applied algorithms for depression, anxiety disorders, bipolar disorder, and schizophrenia to determine the annual incidence of these conditions after the diagnosis of RA, as well as their lifetime and annual period prevalence. Using negative binomial regression models, they compared findings between the 2 cohorts.

The investigators identified 10,206 patients with RA and 50,960 matched individuals from the general population. After adjusting for confounding variables, they found that the incidence of depression was higher in the RA cohort during the study period (incidence rate ratio [IRR], 1.46), as was the incidence of anxiety disorder (IRR, 1.24) and bipolar disorder (IRR, 1.21).

The incidence of schizophrenia did not differ between groups (IRR, 0.96). The incidence rates of psychiatric disorders declined minimally over time. The lifetime and annual period prevalence of depression and anxiety disorder were also higher among patients with RA than the general population.

The authors note that clinicians should be aware that among patients with RA, women and those of lower socioeconomic status are at particularly increased risk for these psychiatric disorders. They suggest that future studies should evaluate the associations between characteristics of RA or its treatments and the risk for psychiatric comorbidity.

Reference

Marrie RA, Hitchon CA, Walld R, et al. Increased burden of psychiatric disorders in rheumatoid arthritis [published online February 13, 2018]. ArthritCare Res. doi:10.1002/acr.23539