Andrea L. Roberts
Results from a 20-year cohort study revealed that women with a history of depression had a more than twofold increased risk for systemic lupus erythematosus compared to those without depression.
These longitudinal study findings, published in JAMA Psychiatry, further support prior evidence that depression may be a causal risk factor for autoimmune disease.
“There is some evidence that depression may increase risk of autoimmune diseases,” Andrea L. Roberts, PhD, of Harvard T. H. Chan School of Public Health, told Healio Psychiatry. “However, there have been relatively few studies that follow people over time to see whether people who are depressed are more likely to develop new cases of autoimmune disease, compared to people who are not depressed. Studies like that provide stronger evidence that depression may increase risk of developing new autoimmune disease.”
Researchers evaluated data collected from two large cohorts of women to determine whether a connection exists between depression and risk for incident systemic lupus erythematosus (SLE).
Roberts and colleagues also examined whether health risk factors — cigarette smoking, BMI, oral contraceptive use, hormone use, alcohol use, exercise or diet — contributed to a higher risk for SLE among participants with vs. without depression. In addition, they conducted additional analyses, one of which examined the association of depression status lagged by an additional 4 years, to lower the chance that associations occurred because SLE caused depression or because depression was an early symptom of SLE.
Over the 20-year follow-up, there 145 cases of SLE among 194,483 women. Women with a history of depression were twice as likely to develop subsequent SLE compared with women without depression (HR = 2.67; 95% CI, 1.91-3.75). Adjusting for covariates only slightly attenuated these association (adjusted HR = 2.45; 95% CI, 1.74-3.45).
The risk for SLE rose with each of the three following depression indicators modeled separately:
- clinical depression diagnosis (HR = 2.19; 95% CI, 1.29-3.71);
- antidepressant use (HR = 2.8; 95% CI, 1.94-4.05); and
- 5-item Mental Health Inventory scores indicating depressed mood (HR = 1.7; 95% CI, 1.18-2.44).
Sensitivity analyses revealed that depression status lagged 4 years (HR = 1.99; 95% CI, 1.32-3) and depression status in 1996 or 1997 (HR = 2.28; 95% CI, 1.54-3.37) were both tied to elevated risk for SLE. In addition, when researchers examined a subsample of women with a date of first SLE symptoms, the date of first symptoms preceded SLE diagnosis by 1 year on average, according to the results.
“Screening of patients with depression for family history and symptoms of lupus may improve its early detection,” Roberts said. “In addition, people with depression are at risk of several inflammation-related diseases. Encouragement of persons with depression to reduce risk factors for inflammation, such as improving diet quality and exercising may reduce their risk for lupus as well as other inflammation-related conditions, such as cardiovascular disease.” – by Savannah Demko
Disclosure: The authors report no relevant financial disclosures.