Tuesday, March 07, 2006

St. John’s Wort for Unexplained Fatigue

For up to 50 percent of people who consult their doctors complaining of fatigue, no physical basis can be found, and no definitive treatment exists. Many physicians and researchers believe that, at least in some cases, unexplained fatigue may be a somatic (physical) symptom of masked depression. St. John’s wort (Hypericum perforatum L., Clusiaceae) has been shown to be effective in alleviating symptoms of tiredness and fatigue in depressed patients (Hübner et al., 1993). Researchers designed a small, uncontrolled, open pilot study to assess the effects of St. John’s wort in 20 people suffering from fatigue of unexplained origin, in order to formulate a hypothesis upon which future, controlled research in this area could be based (Stevinson et al., 1998).

The study participants (17 women and 3 men) all had fatigue that had persisted for at least two weeks, but none considered themselves depressed. Levels of perceived fatigue were established at baseline with visual analog scales (VAS) that were completed both by participants and by the people closest to them (usually their partners). Subjects also completed another 14-item fatigue scale, a 12-item General Health Questionnaire (GHQ), and the Hospital Anxiety and Depression scale (HAD). Results were assessed using the same scales after two weeks and again at the end of the six-week treatment period.

After two weeks of treatment with standardized St. John’s wort extract, subjects’ perceived fatigue was significantly less than that recorded at baseline. After six weeks, fatigue was reduced significantly further. Even though none of the participants considered themselves depressed or anxious, baseline scores indicated that nine were depressed or borderline depressed at the beginning of the study, and that 14 were suffering from anxiety or borderline anxiety. According to the HAD, fatigue improved in seven of the nine participants who were classified as depressed, but in only three of the 10 who were classified as not depressed. By the end of the study, only three subjects could be classified as depressed/borderline, and only five as anxious/borderline.

The authors noted, "The possibility exists … that the improvements in fatigue in this study are an indirect result of the specific effects of Hypericum on depression, with the perceived reduction in fatigue a consequence of the improvement in mood." They suggested that future research should focus on subjects reliably diagnosed as "non-depressed" in order to determine whether the herb has any direct effects on fatigue.

The dosage of St. John’s wort used in the trial was one tablet three times daily of extract standardized to contain 300 mcg total hypericin per tablet (Kira®, manufactured by Lichtwer Pharma UK Ltd). One participant withdrew from the trial because of dizziness, which persisted after discontinuation of St. John’s wort. No other adverse effects were reported. – Evelyn Leigh