In 1953 the Japanese police system was reorganized, centralized, and made more efficient. Law enforcement efforts were intensified, supported by the criminalization of stimulant abuse with the enactment of the Stimulant Control Law in 1951. Rigorous enforcement of subsequent amendments has resulted in more arrests, indictments, and relatively harsh penalties for stimulant offenses, as well as an increase in the number and volume of confiscations. In 1951, 26 percent of those arrested were under age 20 and about half were addicts. By 1954 the nation had about 550,000 chronic stimulant users and 2 million former users. The number of stimulant arrests was relatively stable from 1980 to 1985, leveling off at about 20,000 annually. In 1960 the heavy use of sleeping pills among youths in Tokyo foreshadowed a period of youth drug abuse. Inhalant abuse developed in 1967 and about 40,000 people have been arrested each year since 1975 for offenses related to inhalants. Japan has no diversion programs for drug abuse, although some juveniles are referred to treatment as a kind of probation. Tables and 5 references. (Author abstract modified)