Roberts AL, et al. - In this 20-year cohort study, researchers investigated if depression is associated with an increased incidence of systemic lupus erythematosus (SLE), a paradigmatic, systemic autoimmune disease. Observations suggested a more than twofold subsequent increased risk of SLE among women with a history of depression vs those with no depression, indicating a possible association of depression with an increased risk of SLE.

Methods

• Data from two cohorts of women participating in the Nurses’ Health Study (1996-2012) and the Nurses’ Health Study II (1993-2013) were collected and evaluated.
• Researchers performed data analysis from August 2017 to May 2018.
• They ascertained incident SLE with ≥ 4 American College of Rheumatology criteria by self-report, which was confirmed by medical record review.
• Throughout follow-up, they repeatedly assessed depression according to whether women reported having received a clinician’s diagnosis of depression, regular antidepressant use, or a score of < 60 on the 5-item Mental Health Inventory (MHI-5).
• Women with vs without depression were examined for the presence of correlation of longitudinally assessed health risk factors (eg, cigarette smoking, body mass index, oral contraceptive use, menopause or postmenopausal hormone use, alcohol use, exercise, or diet) with increased SLE risk.
• Risk of SLE was estimated using Cox proportional hazards regression models.
• In addition, they assessed the association of depression lagged by 4 years, and depression status at baseline with incident SLE throughout follow-up.

Results

• Researchers included the data from 194,483 women (28-93 years of age; 93% white).
• SLE occurred in 145 cases during 20 years of follow-up.
• Compared with women with no depression, women with a depression history displayed a subsequent higher risk of SLE (HR, 2.67; 95% CI, 1.91-3.75; P < 0.001).
• The associations were slightly attenuated on adjusting for body mass index, cigarette smoking, and oral contraception and postmenopausal hormone use (adjusted HR, 2.45; 95% CI, 1.74-3.45; P < 0.001).
• They noted elevated SLE risk with each of the three following depression indicators modeled separately: clinician’s diagnosis of depression (HR, 2.19; 95% CI, 1.29-3.71), antidepressant use (HR, 2.80; 95% CI, 1.94-4.05), and MHI-5 scores indicating depressed mood (HR, 1.70; 95% CI, 1.18-2.44).
• When depression status was lagged by 4 years with respect to the outcome (HR, 1.99; 95% CI, 1.32-3.00) and when depression status at baseline was used as the exposure (HR, 2.28; 95% CI, 1.54-3.37), the associations remained strong.