Mood Disorders in Systemic Lupus Erythematosus: Results From an International Inception Cohort Study

Abstract

Objective: To examine the frequency, characteristics, and outcome of mood disorders, as well as clinical and autoantibody associations, in a multiethnic/racial, prospective inception cohort of patients with systemic lupus erythematosus (SLE).

Methods: Patients were assessed annually for mood disorders (4 types, according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) and 18 other neuropsychiatric events. Global disease activity scores (SLE Disease Activity Index 2000 [SLEDAI-2K]), damage scores (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index [SDI]), and Short Form 36 subscales, mental and physical component summary scores were collected. Time to event, linear and ordinal regressions, and multi-state models were used as appropriate.

Results: Among the 1,827 patients with SLE, 88.9% were female, and 48.9% were Caucasian. The mean ± SD age of the patients was 35.1 ± 13.3 years, disease duration was 5.6 ± 4.8 months, and the length of followup was 4.7 ± 3.5 years. During the course of the study, 863 (47.2%) of the 1,827 patients had 1,627 neuropsychiatric events. Mood disorders occurred in 232 (12.7%) of 1,827 patients, and 98 (38.3%) of 256 mood disorder events were attributed to SLE. The estimated cumulative incidence of any mood disorder after 10 years was 17.7% (95% confidence interval 15.1, 20.2%). A greater risk of mood disorder was associated with concurrent neuropsychiatric events (P ≤ 0.01), and a lower risk was associated with Asian race/ethnicity (P = 0.01) and treatment with immunosuppressive drugs (P = 0.003). Mood disorders were associated with lower mental health and mental component summary scores but not with the SLEDAI-2K, SDI, or lupus autoantibodies. Among the 232 patients with depression, 168 (72.4%) were treated with antidepressants. One hundred twenty-six (49.2%) of 256 mood disorders resolved in 117 (50.4%) of 232 patients.

Conclusion: Mood disorders, the second most frequent neuropsychiatric event in patients with SLE, have a negative impact on health-related quality of life and improve over time. The lack of association with global SLE disease activity, cumulative organ damage, and lupus autoantibodies emphasizes the multifactorial etiology of mood disorders and a role for non-lupus-specific therapies.

Figure 1

Kaplan-Meier estimates of the survivor function for time until first mood disorder of any type (with 95% CI) and by attribution (left panel) and by mood disorder type (right panel).

Figure 2

The estimated means of MCS, PCS and mental health subscale scores of the SF-36 at each visit (up to the 10^th followup visit) are illustrated for the following four groups: (i) patients with SLE attributed mood disorder (black lines); (ii) patients with non-SLE attributed mood disorder (red lines) (iii) patients without mood disorder, but with other types of NP events (green lines), (iv) patients without mood disorder and other NP events (blue lines).

Figure 3

Kaplan-Meier estimate of time (with 95% CI) to resolution of all mood disorders (left panel); Distributions of maximum and minimum Likert scale scores observed over followup for 256 mood disorders (right panel).