The use and development of anxiolytics in Japan

More than half of the out-patients in Japanese hospitals receive anxiolytics or hypnotics for basic symptomatic management. Benzodiazepines (BZDs) are the most frequently prescribed by psychiatrists and by internists for the treatment of anxiety symptoms (mainly generalised anxiety disorder, psychosomatic diseases and autonomic dystonia). Although numerous BZDs and their analogues were introduced into the Japanese market during the last three decades, thienodiazepine derivatives have the predominant market share, in contrast to the US and the UK. Approved doses are also lower. The lack of buspirone and SSRIs in the market may contribute to the widespread prescription of BZDs in Japan. Several newer anxiolytic candidates, such as BZD receptor partial agonists and 5-HT1A receptor agonists, are currently in various phases of clinical research in Japan. However, the designs of clinical trials, particularly diagnostic precision, need to be revised.