Background/Purpose: Depression occurs commonly among patients with SLE.  In this study, we used two separate scales to assess depression and determined differences in clinical characteristics and patient-reported disease activity in patients with and without symptoms of depression.

Methods: Patients meeting ACR or SLICC criteria for SLE in a university rheumatology clinic were included. At each visit, patients completed a series of questionnaires: Systemic Lupus Activity Questionnaire (SLAQ), Patient Health Questionnaire (PHQ-9), and the ACR Fibromyalgia (FM) Diagnostic Criteria 2011. To meet criteria for FM, patients had (1) widespread pain score ≥7 and symptom severity score ≥5 or (2) widespread pain score ≥3 and symptom severity score ≥9. Physician measures of disease activity collected at each visit included SLEDAI and physician global assessment (PGA). Depression was defined as PHQ-9 score ≥10. As part of the SLAQ, patients were asked if they were “feeling depressed” in the prior month, with responses of none, mild, moderate, or severe. Differences in clinical characteristics and patient-reported disease activity in patients with and without depression were analyzed by Fisher’s exact test and t-tests.

Results: The analysis included 208 patients with SLE (92% female, mean age 45 years, 22% with FM). Of 175 patients who completed the PHQ-9, 30% met criteria for depression. Of the 208 patients who completed the SLAQ, 47% reported experiencing any depression (mild, moderate, or severe) in the previous month, while 17% reported moderate to severe depression.

Among patients with FM, 66% reported depression by PHQ-9, 33% reported mild depression by SLAQ and 31% reported moderate to severe depression. In contrast, among those without FM, 18% reported depression by PHQ-9, 20% reported mild depression, and 13% reported moderate or severe depression by SLAQ.

Patients with depression reported more fatigue, muscle weakness, muscle pain, swollen joints, stiff joints, anxiety, and forgetfulness (Table 1).  Further, patients with depression had higher overall SLAQ scores, patient-reported disease activity, widespread pain scores, and symptom severity scores. Among patients who met PHQ-9 criteria for moderate-severe depression, clinical SLEDAI, full SLEDAI, and PGA scores were higher than patients without depression.

Conclusion: These data suggest that SLE patients with depression are more symptomatic and have higher perceived disease activity. They also demonstrate a strong association between depression, FM, and some SLE symptoms that often confounds trials and clinical care decisions. Together, these findings suggest that identifying methods to distinguish between these symptoms and target therapy to the underlying pathology will improve the quality of life for patients living with SLE and the comorbid symptoms of fibromyalgia and depression.