Clinical sleep medicine in Japan is still in developing stage. There is no established consensus about what sleep medicine is, what kind of disorders sleep medicine should deal with, who should be involved in practicing sleep medicine, and how sleep disorders should be investigated and treated. In order to make progress to step into the next stage, establishing an identity of clinical sleep medicine is an urgent matter. People in different countries who are tackling with the practice of sleep medicine should find some information in here.

The beginning of Japanese clinical sleep medicine can be dated back to 1990 when polysomnography (PSG) was first covered by the national health insurance. It was achieved by the petitionary activity by Japanese Society of Electroencephalography and Electromyography (currently, Japanese Society of Clinical Neurophysiology), Japanese Society of Sleep Research (JSSR), and The Japan Epilepsy Society. Until that year sleep had been considered one of the subjects of research in psychology, physiology, and psychiatry, and PSG had not been performed routinely for the purpose of clinical diagnosis and treatment. As the Japanese medical care system is virtually controlled by the government, anything without official reimbursement cannot be recognized as clinically necessary; therefore, this was the first step into clinical sleep medicine [1]. However, PSG reimbursement at that time was only 15000 JPY (33000 JPY in 2015), and the manpower resource for PSG remained in the side of physicians who worked without salary in university hospitals as postgraduate students doing clinical sleep research at the same time [2].

JSSR in the 1990s was composed of mainly psychiatrists, neurophysiologists, and psychologists. Among this group of people, only psychiatrists were allowed to directly deal with patients under the Japanese Medical Service Act. Since these psychiatrists did not compose the major portions of psychiatry community, therefore, sleep was not within psychiatrists’ interest except that insomnia widely received psychiatric attention. Although JSSR organized a special symposium about sleep apnea syndrome (SAS) at the 9th Annual Meeting held as early as 1984, they failed to transmit the new knowledge to wider medical community.

On the other hand, some pulmonologists who had been involved in physiological research of sleep apnea started to hold regular meetings organizing Sleep-disordered Breathing Research Group in 1988 , which was differently composed from JSSR in that their members are mostly respiratory physicians and otorhinolaryngologists who are more interested in treatment of SAS. In addition, their approach was based on traditional medical methods and they focused on definition of SAS and its epidemiology at the kickoff point. However, the other important aspects of sleep medicine such as sleep health, circadian rhythm, or sleep disorders other than SAS were beyond their scope.