The U.S. Army, in a search for nonlethal incapacitating agents," tested cannabis-based drugs on GI volunteers throughout the 1960s according to Dr. James Ketchum, the psychiatrist who led the classified research program at Edgewood Arsenal in Maryland. Ketchum retired as a colonel in 1976. He has written a memoir, "Chemical Warfare: Secrets Almost Forgotten," in which he describes experiments conducted at Edgewood and defends the Army's ethical standards. In a talk to the Society of Cannabis Clinicians in Los Angeles last month, Ketchum recounted to 20 doctors the Army's experiments with cannabinoid drugs. Only a small fraction of Ketchum's work at Edgewood involved THC derivatives. Ketchum says he was motivated to write his memoir because the media has conflated the ethical, scientific drug studies conducted by the Army on knowing volunteers with the kinky, unsafe drug studies conducted by the CIA on unwitting civilians. "None, to my knowledge, returned home with a significant injury or illness attributable to chemical exposure," Ketchum says. "Nevertheless, years later, a few former volunteers did claim that the testing had caused them to suffer from some malady." Those claims came from subjects exposed to agents other than EA 2233, he says.