Army doctors gave soldier volunteers synthetic marijuana, LSD and two dozen other psychoactive drugs during experiments aimed at developing chemical weapons that could incapacitate enemy soldiers, a psychiatrist who performed the research says in a new memoir.
The program, which ran at the Army's Edgewood, Md., arsenal from 1955 until about 1972, concluded that counterculture staples such as acid and pot were either too unpredictable or too mellow to be useful as weapons, psychiatrist James Ketchum said in an interview.

The program did yield one hallucinogenic weapon: softball-size artillery rounds that were filled with powdered quinuclidinyl benzilate or BZ, a deliriant of the belladonnoid family that had placed some research subjects in a sleeplike state and left them impaired for days.

Ketchum says the BZ bombs were stockpiled at an Army arsenal in Arkansas but never deployed. They were later destroyed.

The Army acknowledged the program's existence in 1975. Follow-up studies by the Army in 1978 and the National Academy of Sciences in 1981 found that volunteers suffered no long-term effects.