Randomised controlled trials of homeopathy in hyperactive children: treatment procedure leads to an unconventional study design. Experience with open-label homeopathic treatment preceding the Swiss ADHD placebo controlled, randomised, double-blind, cross-over trial.
Frei H, Everts R, von Ammon K, Kaufmann F, Walther D, Schmitz SF, Collenberg M, Steinlin M, Lim C, Thurneysen A. Homeopathy. 2007 Jan; 96(1):35-41.