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Homeopathy for mental fatigue: a double blind placebo controlled trial

Mental fatigue is a problem experienced by many people. Potassium phosphate is traditionally indicated in homeopathic sources for cognitive problems including inattention and concentration difficulties. A commonly available off the shelf treatment is Kalium Phosphoricum (Kali Phos); however, there has been no independent research into its efficacy. This research was conducted as part of a programme evaluating homeopathy for attention deficit/hyperactivity disorder, funded by the Department of Health.

We recruited 86 student and staff volunteers with self-reported mental fatigue, all from within the University of York, to take part in a triple-blind, cross-over, placebo-controlled clinical trial. The volunteers were randomised to receive either kali phos 6x or an identical placebo and then asked to take a psychological test of attention (Stroop Colour-Word Test). One week later the volunteers crossed over and took the other preparation before repeating the test.

The results of this study showed that there was no evidence to suggest Kali phos 6x is effective in reducing mental fatigue. Although the current study failed to find any significant effect, this may be attributable to the methodological flaws in the implementation of the outcome measure causing a ceiling effect, so a treatment effect cannot be ruled out. The trial is registered at ISRCTN (No. ISRCTN16521161) and the paper has been published.


Funder(s): NIHR post-doctoral fellowship
Start Date: 2005
Expiry Date: 2009


Internal Staff


Health Services Policy Research in the Department of Health Sciences