Survey of current trends in the abuse of psychotropic substances and plants in Japan.

In recent years, many analogs of narcotics have been widely distributed as easily available psychotropic substances and have become a serious problem in Japan. To counter the spread of these non-controlled substances, the Pharmaceutical Affairs Law in Japan was amended in 2006 to establish a new category, "designated substances", to more strictly control these psychotropic substances. Fifty-one substances have been listed in this category as of December 2010. However, many new analogs have appeared, one after the other. Although the distribution of tryptamine-type designer drugs has decreased since the amendment of the law, the distribution of cathinone derivatives, as well as of phenetylamine-type and piperazine-type designer drugs, has increased. Moreover, non-controlled psychotropic plants have become popular in place of chemical psychotropic substances, which are now subject to stricter controls. Additionally, since 2008, new herbal products containing synthetic cannabinoids (for example, a brand named "Spice") have appeared. Sixteen synthetic cannabinoids, classified into four groups, have been detected in products purchased up to December 2010 via Japanese-based websites. The distribution of products containing the psychoactive substances described above (so-called "legal highs" in European countries) is a worldwide problem. In this review, we survey current trends in the abuse of psychotropic substances and plants in Japan, focusing especially on synthetic cannabinoids, cathinone derivatives and psychotropic plants.