Open-label study of s-citalopram therapy of chronic fatigue syndrome and co-morbid major depressive disorder.

OBJECTIVE Chronic fatigue syndrome (CFS) is a debilitating disorder with prominent symptoms of malaise, fatigue, myalgia, arthralgia, and impaired concentration. The symptoms of CFS may often overlap those of Major Depressive Disorder (MDD). Treatment of CFS has generally been disappointing. We hypothesized that s-citalopram therapy may improve the symptoms of both disorders in CFS patients with co-morbid depression. METHODS 16 patients received s-citalopram 10 mg to 20 mg daily for up to 12 weeks. Outcome measures of CFS included the Chalder Fatigue Questionnaire (CFQ), the multi-dimensional Fatigue Impact Scale (FIS), the CFS symptom rating (CFS-SR) 100 mm visual analogue scale, and the clinical global impressions severity (CGI/S) and change (CGI/C) ratings. Secondary outcomes of MDD included the Hamilton Depression Rating (HAM-D), Beck Depression Inventory (BDI), and the CGI/S and CGI/C ratings of MDD. RESULTS We observed reductions in the mean CFQ score (p<0.0005), FIS score (p<0.0005), and CGI/S (p<0.0005) and CGI/C (p<0.0005) ratings over time. There was a significant improvement in 5 of the 8 CFS-SR symptoms: post-exertion malaise (p=0.001), headaches (p<0.0005), un-refreshing sleep (p<0.0005), and impaired memory and concentration (p<0.0005). There was also a reduction in mean HAM-D (p<0.0005), BDI (p<0.0005), CGI/S (p=0.001) and CGI/C (p<0.0005) ratings of MDD. LIMITATIONS The sample size was limited and the study design was not double-blind or placebo controlled. CONCLUSION We observed a significant reduction in both CFS and co-morbid MDD symptom severity ratings, and improvement in 5 of 8 core somatic symptoms of CFS during s-citalopram therapy.