Changes of clinical symptoms in patients with new psychoactive substance (NPS)-related disorders from fiscal year 2012 to 2014: A study in hospitals specializing in the treatment of addiction.

Aims: The use of new psychoactive substances (NPS) has become increasingly widespread over the last decade, in Japan and internationally. NPS are associated with a range of increasingly serious clinical, public, and social issues. Political measures to ameliorate the effects of NPS in Japan have focused on tightening regulation rather than establishing treatment methods.