The Relationship Between Depression and Sleep Disturbances: A Japanese Nationwide General Population Survey

Yoshitaka Kaneita, M.D.; Takashi Ohida, M.D.; Makoto Uchiyama, M.D.; Shinji Takemura, Ph.D.; Kazuo Kawahara, M.D.; Eise Yokoyama, M.D.; Takeo Miyake, M.D.; Satoru Harano, M.D.; Kenshu Suzuki, M.D.; and Toshiharu Fujita, M.D.

Objective: Among the existing epidemiologic studies that have examined the relationship between depression and sleep disturbances, there are few nationwide studies that have been conducted on subjects representing the general population. The present study was therefore conducted to clarify the relationship between depression and sleep disturbances, in particular the relationship between depression and both sleep duration and subjective sleep sufficiency, using a large sample representative of the general population.

Method: The survey was conducted in June 2000, using self-administered questionnaires, targeting a population that was selected randomly from among 300 communities throughout Japan. Among the respondents, data from 24,686 individuals aged 20 years or older were analyzed. The Center for Epidemiologic Studies Depression Scale was used to assess the presence of depression. Sleep status, including sleep duration, subjective sleep sufficiency, and the presence or absence of insomnia symptoms, was evaluated.

Results: Those whose sleep duration was less than 6 hours and those whose sleep duration was 8 hours or more tended to be more depressed than those whose sleep duration was between 6 and 8 hours. Thus, sleep duration exhibited a U-shaped association with symptoms of depression. As subjective sleep sufficiency decreased, symptoms of depression increased, indicating a linear inverse-proportional relationship.

Conclusion: The fact that sleep duration and subjective sleep sufficiency exhibited different relationships with symptoms of depression indicates that these 2 sleep parameters each have their own significance with regard to depression. These findings may be useful in the medical management of mental diseases.

(J Clin Psychiatry 2006;67:196-203)

Received Jan. 12, 2005; accepted June 14, 2005. From the Department of Public Health, School of Medicine, Nihon University, Tokyo (Drs. Kaneita, Ohida, Yokoyama, Miyake, Harano, and Suzuki); the Department of Psychophysiology, National Institute of Mental Health, National Center of Neurology and Psychiatry, Ichikawa (Dr. Uchiyama); the Departments of Public Health Policy (Dr. Takemura) and Epidemiology (Dr. Fujita), National Institute of Public Health, Wako; and the Department of Health Policy Science, Graduate School of Medical and Dental Science, Tokyo Medical and Dental University, Tokyo (Dr. Kawahara), Japan.

This study was part of the Active Survey on Health and Welfare conducted by the Statistics and Information Department of the Ministry of Health, Labour and Welfare of the Japanese Government and was supported by a Health Science Research Grant from the Ministry of Health, Labour and Welfare.

The authors report no other financial affiliation or relationship relevant to the subject of this article.

We would like to thank Ms. Hiromi Sekine for her help with manuscript preparation.

Corresponding author and reprints: Yoshitaka Kaneita, M.D., Department of Public Health, School of Medicine, Nihon University, 30-1, Ohyaguchikamimachi, Itabashi-ku, Tokyo 173-8610, Japan (e-mail: kaneita@med.nihon-u.ac.jp).