The history of administering mind-altering drugs to psychiatric patients has been an intensely complicated and controversial story. But no matter what side of the drug debate you happen to find yourself on, the two deaths that resulted from a drug-filled psychotherapy session in Germany this weekend have exposed the necessity of taking extreme caution in administering and regulating otherwise illicit drugs for psychiatric purposes.

50-year old Garri Rober admitted to having given a 12-patient psychotherapy class a “cocktail of drugs” at his home and medical practice in Berlin on Saturday – a cocktail that may have included heroin, MDMA, and amphetamines and resulted in 2 deaths and a coma. Rober, who’s been arrested since the incident, operated an alternative medical practice and says he’s interested in “depth psychology, bodywork and art therapy, and spiritual crises.”

Such experimentation is not new. Harvard Professor Timothy Leary once crusaded around the country boasting the therapeutic benefits of LSD, Swiss psychedelic scientist Albert Hofman petitioned in favor of the controlled use of psychedelic drugs in therapy before his death, and Swiss physician Samuel Widmer’s use of psycholytic substances in therapy has earned him a cult following that includes the likes of Rober himself. And on a more benign scale, the legalization of marijuana for medicinal purposes has gained overwhelming support in recent years.

The near impossibility of differentiating a quack from a genius -- a disaster from a blessing -- makes such therapeutic experimentation a constant game of Russian roulette. The caution exercised by scientists like Albert Hofman versus the recklessness shown by doctors like Rober will provide endless fuel for a medical debate that will likely never see an end.