Objective. This study was designed to assess the effects of corticosteroids on select aspects of nervous system functioning, specifically, cognition and mood, as well as disease–related symptoms in individual patients with mild systemic lupus erythematosus (SLE) and mild neuropsychiatric (NP) symptoms.
Methods. Ten women who had not been taking corticosteroids for at least 6 months were selected from a referral–based lupus clinic to participate in an N of 1 double–blind, controlled trial consisting of 3 randomly assigned drug/placebo pairings, with a drug dose of 0.5 mg/kg of prednisone daily.
Results. Analysis of variance on the group data yielded significant positive drug effects for cognition (P = 0.02), mood (P = 0.003), and SLE symptom ratings (P = 0.0002). Drug efficacy was also evaluated by an objective decision rule, which yielded evidence of overall drug benefit in 5 of the 8 patients who completed the trial, and a deleterious drug effect in 1 patient. Posttrial clinical results indicated that for the 8 women who completed the trial, “acceptable” decisions, leading to remission of SLE symptoms or appropriate withholding of steroids, were made on the basis of this rule.
Conclusion. Improvement in cognition, mood, and/or SLE symptom ratings can be observed following brief exposure to relatively low doses of corticosteroids in individual women with mild SLE; these persist over repeated drug exposure. The current application of N of 1 methodology represents the first systematic study of steroid efficacy in central nervous system (CNS)—related problems in SLE. The results can now be applied to the design of randomized, controlled trials of the effects of corticosteroids on CNS function in SLE.