October 20, 2020
2 min read
Depression is associated with an increased risk for seronegative rheumatoid arthritis, suggesting a link that is unexplained by previous lifestyle factors, according to data published in Arthritis Care & Researchers.
Jeffrey A. Sparks
“Previous studies suggest that depression and other mental health disorders may contribute to systemic inflammation and chronic disease risk,” Jeffrey A. Sparks, MD, MMSc, of Brigham and Women’s Hospital and Harvard Medical School, told Healio Rheumatology. “We were interested in the possible connection between depression and rheumatoid arthritis as a prototypic immune disorder characterized by systemic inflammation.”
“Our study was ideal to pursue this analysis since it had a large sample size, repeated measures of depression, and lengthy follow-up,” he added. “Importantly, we were able to incorporate a time separation between depression and RA measures to ensure findings were not due to early RA symptoms causing depressive symptoms.”
To analyze the link between depression and the risk for RA, based on serologic phenotype, Sparks and colleagues conducted a cohort study using data from the 1992-2014 Nurses’ Health Study (NHS) and the 1993-2015 NHSII. The researchers used a composite definition of depression, including clinician diagnosis, regular antidepressant use and/or a Mental Health Inventory5 score of less than 60 by timeupdated questionnaires during followup. Cases of RA were confirmed through medical review.
Data on covariates, including smoking status, diet and BMI, were obtained using questionnaires. The researchers used Cox regression to estimate hazard ratios for RA — overall and for serologic phenotypes — based on depression status, adjusting for confounders. In addition, all analyses included a time separation between depression assessments and the window for RA risk of at least 4 years. This lowered the possibility of any associations being explained by early RA symptoms causing depressive symptoms, the researchers wrote.
Sparks and colleagues analyzed data from 195,358 women and identified a total of 858 cases of RA over 3,087,556 person-years. Among these cases, 65% were seropositive.
According to the researchers, women with depression demonstrated multivariable hazard ratios of 1.28 (95% CI, 1.1-1.48) for all RA, 1.12 (95% CI, 0.931.35) for seropositive RA and 1.63 (95% CI, 1.272.09) for seronegative RA, all compared to those without depression. When analyzing components of the composite depression exposure variable, regular antidepressant use was not associated with later seropositive RA (HR = 1.21; 95% CI, 0.97-1.49), but was linked to seronegative RA (HR = 1.75; 95% CI, 1.322.32).
“We found that depression may be a potentially novel risk factor for RA, particularly for seronegative RA, which has relatively few known risk factors,” Sparks said. “These findings suggest that mental health may be important in the pathogenesis of this RA subtype. Patients with depression be a population at higher risk for RA that could be considered for future screening or prevention strategies.”