The Relationship between Sleep Time and Mental Health Problems According to the Strengths and Difficulties Questionnaire in Children after an Earthquake Disaster: The Fukushima Health Management Survey.

Shuntaro Itagaki,Yuriko Suzuki,Seiji Yasumura,Tetsuya Ohira,Itaru Miura,Hirobumi Mashiko,Hirooki Yabe,Masaharu Maeda,Tetsuya Shiga,Masato Nagai

doi:10.3390/ijerph15040633

Abstract

A cross-sectional study was performed on the adverse effects of sleep time on the mental health of children after the Great East Japan Earthquake and subsequent nuclear reactor accident in March 2011. The target participants were children aged 4–15 years living inside the government-designated evacuation zone as of 11 March 2011 (n = 29,585). The participants’ parents/guardians completed the Strengths and Difficulties Questionnaire (SDQ) and sleep time data were obtained from the 2011 Fukushima Health Management Survey. A total of 18,745 valid responses were returned. We excluded questionnaires with incomplete answers leaving 13,272 responses for the final analysis. First, we divided the children into three age groups for analysis. Second, we divided each age group into four or five groups based on sleep time per day. We used SDQ scores ≥16 to indicate a high risk of mental health problems. In the 4–6-year-old group, those with a sleep time of <9 h had a higher risk. In the 7–12-year-old group, those with ≥10 h of sleep time had a higher risk. In the 13–15-year-old group, those with ≥9 h of sleep time had a higher risk. Shorter sleep time was associated with a higher risk of mental health in 4–6-year-olds. On the other hand, oversleeping was associated with a high risk of mental health in 7–15-year-olds.

Highlights

The effects of the Great East Japan Earthquake and subsequent nuclear accident at TokyoElectric Power Company’s Fukushima Daiichi Nuclear Power Plant which occurred in March 2011, are expected to be long term, contributing to ongoing anxiety among the residents of FukushimaPrefecture
We focused on the relationship between disaster and sleep time because disturbance of the sleeping habits of children has been associated with the risk of developing lifestyle diseases in the future, and examining the degree of risk is important to accumulate scientific knowledge, and to provide appropriate care
Tsunami experience and nuclear accident experience were not related to sleep time in the 4–6-year-old age group

Summary

Introduction

The effects of the Great East Japan Earthquake and subsequent nuclear accident at TokyoElectric Power Company’s Fukushima Daiichi Nuclear Power Plant which occurred in March 2011, are expected to be long term, contributing to ongoing anxiety among the residents of FukushimaPrefecture. Electric Power Company’s Fukushima Daiichi Nuclear Power Plant which occurred in March 2011, are expected to be long term, contributing to ongoing anxiety among the residents of Fukushima. A 20 km-radius exclusion zone around the reactor and areas where the cumulative annual dose of radiation threatens to reach 20 mSv have been established by the government as planned evacuation zones; the residents of these areas have been forced to live either elsewhere in Fukushima or move outside the prefecture as evacuees. Fukushima Prefecture has been threatened by low-dose radioactivity since this nuclear accident occurred. A major long-term health effect of the previous Chernobyl nuclear disaster has been the disruption of mental and physical processes [1]. Anxieties over radiation, unexplained physical symptoms, and subjective health concerns have all been identified among residents in the exposed areas [2]

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