Correspondence to Dr David McDuff, Psychiatry, University of Maryland School of Medicine, Baltimore MD 21201, USA; dmcduff52{at}gmail.com Background Substances from various classes may be used for ...

A little more than a year ago, on a trip to Nairobi, Kenya, some colleagues and I met a 12-year-old Masai boy named Richard Turere, who told us a fascinating story. His family raises livestock on the ...