Studies on new jail admissions conducted in 1969, 1971, and 1973 indicated a sharp decrease in heroin use among male inmates in the District of Columbia in 1973. In the jail study conducted in 1969 among 225 inmates, 45% reported to be addicted to heroin, in 1971, 47% of the 150 inmates reported to be addicted, as compared to only 22% of the 200 inmates in 1973. Only 38% of the addict-inmates in 1969 reported ever receiving treatment for their addiction, while 62% in 1971 and 64% in 1973 reported receiving treatment.