Abstract
Japan has experienced two epidemics of methamphetamine use that are quite different in their backgrounds. Japan now has reached a plateau in substance use for the 10 years in which problems of methamphetamine and volatile solvent use stabilized at high levels and those of cannabis and opiates at low levels. The most common and detrimental use pattern is the one which is initiated at younger ages with organic solvents and develops later into methamphetamine use.