Author(s)

Kai Wada, Hiroko Kuroda, Miyo Nakade, Hitomi Takeuchi, Tetsuo Harada

Department of Nutritional Management, Faculty of Health and Nutrition, Tokai-Gakuen University, Miyoshi, Japan.
Laboratory of Environmental Physiology, Graduate School of Integrated Arts and Sciences, Kochi University, Kochi, Japan.

This study aims, first, to determine the relationship between Post Traumatic Stress Disorder (PTSD) and current circadian typology and sleep habits of adults who experienced the Great Hanshin-Awaji Earthquake in their childhood in January 1995. An integrated questionnaire was administered to 275 university students (females: 173, males: 93, unknown: 9) aged 19 - 37 (mean age: 21.9 years) in Hyogo Prefecture, Japan. The questionnaire consisted of basic questions about attributes, questions on sleep habits and sleep quality (Monroe’s sleep quality index), the Torsvall-?kerstedt Diurnal Type Scale and the Impact of Event Scale-Revised (IES-R) to obtain PTSD scores. Participants who scored 25 or more in the IES-R were placed in a high-traumatic group (HTG) and those who scored less than 25 were placed in a low-traumatic group (LTG). HTG participants exhibited significantly worse sleep quality than LTG participants (p < 0.001). Although there was no significant difference in sleep latency (p > 0.05), HTG participants woke more frequently during sleep (p < 0.001) and had more difficulty falling asleep (p = 0.001) than LHG participants. Significantly more LTG participants fell asleep easily and slept deeply than HTG participants (p = 0.005, p = 0.011). Only among females, HTG participants were more evening-typed than LTG participants (p = 0.035). These results suggest that people who suffered a disaster in childhood and currently have PTSD have difficulty achieving high sleep quality. Evening-type lifestyles may reinforce the symptoms of PTSD. The study aims, second, to examine the effects of intervention for one month using a leaflet to promote the morning-typed life for persons who suffered natural disaster entitled “Go to bed early, Get up early and Do not forget to have a breakfast for getting three benefits!”. Only one person was over the cutoff point (between 24 and 25) before intervention. This high-traumatic person’s comprehensive sleep health tended to be improved through the intervention (p = 0.052). Such intervention to improve their quality of sleep and promote a morning-typed lifestyle may be an effective way to reduce PTSD symptoms.

Natural Disasters; Victims; PTSD; Sleep Quality; Circadian Typology

Wada, K. , Kuroda, H. , Nakade, M. , Takeuchi, H. and Harada, T. (2014) Epidemiological Studies on the Relationship between PTSD Symptoms and Circadian Typology and Mental/Sleep Health of Young People Who Suffered a Natural Disaster, Great Hanshin-Awaji Earthquake. Natural Science, 6, 338-350. doi: 10.4236/ns.2014.65035.