Psychiatry and Clinical Neurosciences (2002), 56, 235–236

Lifestyle and Environment

An examination of sleep health, lifestyle and mentalhealth in junior high school students

HIDEKI TANAKA, phd,1 KAZUHIKO TAIRA, phd,3 MASASHI ARAKAWA, ma,3

ATUSHI MASUDA, ma,3 YUKARI YAMAMOTO, phd,2 YOKO KOMODA, phd,2

HATHUKO KADEGARU, ma3 AND SHUICHIRO SHIRAKAWA, phd2

1Department of Clinical Psychology, Faculty of Human and Social Environment, Hiroshima InternationalUniversity, Hiroshima, 2Department of Psychogeriatrics, National Institute of Mental Health, National Center of Neurology and Psychiatry, Chiba and 3Department of Life Long Health Promotion College of RyukyusUniversity, Okinawa, Japan

Abstract The factors that influence sleep health and mental health in junior high school students’ lifestyleswas examined. The proportion of students who replied that they feel bad in the morning, andwho do not have breakfast was significantly higher in poor sleepers. The proportion of studentswho regularly take exercise was significantly lower among poor sleepers. Compared with goodsleepers, poor sleepers had a higher number of illnesses and their General Health Questionnairescore was worse. The study’s results suggest that sleep health is closely related to both physicaland mental health, and that habits such as exercise, and regular sleeping and eating, are impor-tant for maintaining and improving students’ sleep health.

Key words junior high school students, mental health, nodding, sleep habits, sleep health.

INTRODUCTION

It has been pointed out previously that lack of sleepor having sleep disorders may suppress brain functionand diminish the ability to learn, concentrate orcontrol the mind.1,2 It is often observed that today’sadolescents have nocturnal lifestyles and shortersleeping hours. The present study examined thefactors that influence sleep health and mental healthin junior high school students’ lifestyles.

METHODS

A survey of 805 students attending junior highschools in Okinawa prefecture was carried out duringthe autumn 2001. By analysing the questionnaire3

about their lifestyles and sleep health, five risk factorsin sleep health were determined, which were classifiedas follows: (i) sleep maintenance problems; (ii) parasomnia-like problems; (iii) sleep apnea; (iv) dif-

ficulty in waking up; and (v) difficulty in initiatingsleep. Furthermore, the total score of each factor wascalculated according to a sleep health risk index,3,4

which categorized 200 (25% higher ranking) subjectsas being in the poor sleep health group, and 200 (25%lower ranking) subjects as being in the good sleephealth group. These two groups were then compared.Mental health was assessed using the General HealthQuestionnaire (GHQ).5

RESULTS

The sleep health risk index of the poor sleep healthgroup was significantly higher than that of the goodsleep health group (0.8 ± 0.3 vs 3.9 ± 1.1; P < 0.01).Figure 1 compares the lifestyles of the good sleepgroup with the poor sleep group. The rate of studentswho go to bed and wake up irregularly was signifi-cantly higher in the poor sleep health group. Further-more, the proportion of students who regularly takeexercise was significantly lower and the number ofstudents who do not eat breakfast was significantlyhigher in the poor sleep group. Figure 2 comparesboth physical and mental health of the good sleepgroup with the poor sleep group. The proportion of

Correspondence address: Hideki Tanaka, Department of ClinicalPsychology, Faculty of Human and Social Environment, HiroshimaInternational University, 555-36 Gakuendai, Kurose, Kamogun,Hiroshima 724-0695, Japan. Email: t-hideki@he.hirokoku-u.ac.jp

236 H. Tanaka et al.

students who reported that they felt bad in themorning and the proportion of students who dozedduring the day was significantly higher in the poorsleep health group. Compared with the good sleepgroup, the poor sleep group had a higher number ofillnesses and the GHQ score was worse. The GHQscore and sleep health risk index had an importantsignificant positive correlation (0.33, P < 0.01).

DISCUSSION

A recent survey of 3754 junior high school studentshas reported that the habit of staying up late not onlycontributes to students’ sleepiness during classes, butalso results in the deterioration of sleep health, poordietary habits, and increased incidence of illness.6 Fur-thermore, the results of the research demonstratedthat the aggravation of sleep health caused by thedelay of the sleep phase, sleep debts and irregularityof sleep habits, is related to the lack of having break-fast, and poor physical and mental health. In short,the deterioration of sleep health is closely related tothe physical and mental health of junior high schoolstudents. The issue of sleep quality at this stage in lifeis not a problem pertinent only to educators; it is ofvital importance to life-long health management. Theresults of the present study suggest that habits such as

exercise and regular sleeping and eating are impor-tant in maintaining and improving sleep health, andthat sleep health is closely related to junior highschool students’ physical and mental health.

REFERENCES

1. Dinges DF. An overview of sleepiness and accidents. J.Sleep Res. 1995; 4: 4–14.

2. Bonnet MH. Sleep deprivation. In: Kryger MH, Roth T,Dement WC (eds). Principles and Practice of Sleep Medi-cine. W.B. Saunders, Philadelphia, 1994; 50–67.

3. Tanaka H, Taira K, Uezu E et al. An examination of sleep health and life habits of elderly persons in long-lifeprefecture Okinawa and Megalopolitan Tokyo from theviewpoint of area differences. Jpn. J. Geriatric Psychiatry2000; 11: 425–433 (in Japanese with English abstract).

4. Tanaka H, Taira K, Arakawa M et al. Sleep habits ofjunior high school students of Okinawa prefecture insummer vacation: An examination from the viewpoint oflife-long health. Jpn. J. Mental Health 2000; 46: 65–71 (inJapanese with English abstract).

5. Goldberg DP, Hillier VF. A scaled version of the General Health Questionnaire. Psychol. Med. 1979; 9:139–145.

6. Arakawa M, Taira K, Tanaka H et al. A survey of juniorhigh school students’ sleep habits and lifestyle inOkinawa. Psychiatry Clin. Neurosci. 2001; 55: 211–212.

Figure 1. Lifestyle comparison between good and poorsleepers. Figure 2. Comparison of nodding, and physical and mental

health between groups.