Masaharu Maeda

Health effects of radiation and other health problems in the aftermath of nuclear accidents, with an emphasis on Fukushima

437 nuclear power plants are in operation at present around the world to meet increasing energy demands. Unfortunately, five major nuclear accidents have occurred in the past--ie, at Kyshtym (Russia [then USSR], 1957), Windscale Piles (UK, 1957), Three Mile Island (USA, 1979), Chernobyl (Ukraine [then USSR], 1986), and Fukushima (Japan, 2011). The effects of these accidents on individuals and societies are diverse and enduring. Accumulated evidence about radiation health effects on atomic bomb survivors and other radiation-exposed people has formed the basis for national and international regulations about radiation protection. However, past experiences suggest that common issues were not necessarily physical health problems directly attributable to radiation exposure, but rather psychological and social effects. Additionally, evacuation and long-term displacement created severe health-care problems for the most vulnerable people, such as hospital inpatients and elderly people.

Sleep Findings in Young Adult Patients with Posttraumatic Stress Disorder

BACKGROUND Laboratory sleep studies in posttraumatic stress disorder (PTSD) have not provided consistent evidence of sleep disturbance, despite apparent sleep complaints. Most of these studies have investigated middle-aged chronic PTSD subjects with a high prevalence of comorbidities such as substance dependence and/or personality disorder. METHODS Ten young adult PTSD patients (aged 23.4 +/- 6.1 years) without comorbidities of substance dependence and/or personality disorder underwent 2-night polysomnographic recordings. These sleep measures were compared with those of normal control subjects and were correlated with PTSD symptoms. RESULTS Posttraumatic stress disorder patients demonstrated significantly poorer sleep, reduced sleep efficiency caused by increased wake time after sleep onset, and increased awakening from rapid eye movement (REM) sleep (REM interruption). We found significant positive correlations between the severity of trauma-related nightmare complaints and the percentage of REM interruption, as well as wake time after sleep onset. CONCLUSIONS The results indicate that trauma-related nightmares are an important factor resulting in increased REM interruptions and wake time after sleep onset in PTSD.

Psychological distress and the perception of radiation risks: the Fukushima health management survey.

Abstract Objective To assess relationships between the perception of radiation risks and psychological distress among evacuees from the Fukushima nuclear power plant disaster. Methods We analysed cross-sectional data from a survey of evacuees conducted in 2012. Psychological distress was classified as present or absent based on the K6 scale. Respondents recorded their views about the health risks of exposure to ionizing radiation, including immediate, delayed and genetic (inherited) health effects, on a four-point Likert scale. We examined associations between psychological distress and risk perception in logistic regression models. Age, gender, educational attainment, history of mental illness and the consequences of the disaster for employment and living conditions were potential confounders. Findings Out of the 180 604 people who received the questionnaire, we included 59 807 responses in our sample. There were 8717 respondents reporting psychological distress. Respondents who believed that radiation exposure was very likely to cause health effects were significantly more likely to be psychologically distressed than other respondents: odds ratio (OR) 1.64 (99.9% confidence interval, CI: 1.42–1.89) for immediate effects; OR: 1.48 (99.9% CI: 1.32–1.67) for delayed effects and OR: 2.17 (99.9% CI: 1.94–2.42) for genetic (inherited) effects. Similar results were obtained after controlling for individual characteristics and disaster-related stressors. Conclusion Among evacuees of the Fukushima nuclear disaster, concern about radiation risks was associated with psychological distress.

Stigma associated with schizophrenia: Cultural comparison of social distance in Japan and China

Aims:  The aim of the present study was to investigate social attitudes toward schizophrenia in Japan and China in view of social distance and knowledge of psychiatry, as well as sociocultural aspects.

Suicide rates in the aftermath of the 2011 earthquake in Japan

The March, 2011 earthquake and tsunami that affected the Iwate, Miyagi, and Fukushima prefectures led to a nuclear power plant accident at the Fukushima Daiichi facility. 13 municipalities were designated as evacuation areas from radiation exposure, and 210 000 residents were evacuated. As of January, 2015, 120 000 Fukushima residents remain evacuated, with some residents deciding to relocate permanently. The Fukushima Medical University Health Management Group conducted mental health surveys with roughly 185 000 evacuees. Among those surveyed, 14·6% in 2011, 11·7% in 2012, and 10·3% in 2013 screened positive for high distress, and 21·6% in 2011, 17·4% in 2012, and 17·2% in 2013 had probable post-traumatic stress disorder (PTSD). In community samples throughout Japan, 3·0% of people reported high distress and 1·3% with trauma exposure had PTSD. Because of stigma, distress, and PTSD from the nuclear disaster, providing mental health care for Fukushima evacuees became a priority. Comprehensive measures were implemented, including supportive telephone calls by clinical psychologists, public health nurses, and psychiatric social workers to more than 3000 people per year, whose questionnaires on the Fukushima Medical University survey indicated substantial symptomatology or who requested help. Six mental care centres have been established in Fukushima since 2012 and more than 500 dialogue workshops with radiation health experts have been carried out in aff ected communities over a 3·5 year period. The standardised suicide mortality ratio decreased during the first 2 years after the disaster in each affected prefecture compared with 2010 (table), and then rose in 2014 to the pre-disaster level in Iwate and Miyagi prefectures and exceeded it in the Fukushima prefecture. In Japan as a whole, suicide prevalence is declining slightly. A similar pattern was seen after the 1995 Hanshin-Awaji earthquake, with suicide prevalence decreasing during the first 2 years and then increasing. It is conceivable that during 2011, when the evacuations and displacements peaked, there was both great attention from national and international authorities and a collective feeling of concern and altruism, similar to experiences during and just after World Wars I and II in the USA, France, west Germany, and Japan. However, once the new reality caused by the triple disaster set in, increased demoralisation and anxiety, combined with restricted employment and movement of young families to urban areas, triggered a rise in suicide in Fukushima that the mental health intervention programmes were unable to offset. Thus, long-term efforts to assist in psychological recovery are needed. We thank the National Health Fund for Children and Adults Aff ected by the Nuclear Incident.

Three-year trend survey of psychological distress, post-traumatic stress, and problem drinking among residents in the evacuation zone after the Fukushima Daiichi Nuclear Power Plant accident [The Fukushima Health Management Survey].

Prolonged periods of instability in terms of living environment can lead to a serious increase in mental health issues among disaster‐affected individuals. The aim of this study was to assess long‐term trends in mental health among adult residents in a nuclear‐disaster‐affected area.

Clinical evaluation of paroxetine in post‐traumatic stress disorder (PTSD): 52‐week, non‐comparative open‐label study for clinical use experience

Aim:  The present study was a 52‐week, non‐comparative, open‐label study of flexible dose paroxetine (20–40 mg) in 52 Japanese post‐traumatic stress disorder (PTSD) patients in order to obtain clinical experience regarding efficacy and safety in regular clinical practice.

Adolescent vulnerability to PTSD and effects of community-based intervention: Longitudinal study among adolescent survivors of the Ehime Maru sea accident

The aim of the present study was to examine the psychological impact on adolescent survivors of a maritime disaster that resulted in the deaths of nine people, including four high school students, and the effects of psychiatric intervention for the survivors.

Severe Psychological Distress of Evacuees in Evacuation Zone Caused by the Fukushima Daiichi Nuclear Power Plant Accident: The Fukushima Health Management Survey

Background Following the Great East Japan Earthquake on March 11, 2011, the nuclear disaster at the Fukushima Daiichi Nuclear Power Plant has continued to affect the mental health status of residents in the evacuation zone. To examine the mental health status of evacuee after the nuclear accident, we conducted the Mental Health and Lifestyle Survey as part of the ongoing Fukushima Health Management Survey. Methods We measured mental health status using the Kessler 6-item psychological distress scale (K6) in a total of 73,569 (response rate: 40.7%) evacuees aged 15 and over who lived in the evacuation zone in Fukushima Prefecture. We then dichotomized responders using a 12/13 cutoff on the K6, and compared the proportion of K6 scores ≥13 and ≤12 in each risk factor including demographic information, socioeconomic variables, and disaster-related variables. We also performed bivariate analyses between mental health status and possible risk factors using the chi-square test. Furthermore, we performed multivariate regression analysis using modified Poisson regression models. Results The median K6 score was 5 (interquartile range: 1–10). The number of psychological distress was 8,717 (14.6%). We found that significant differences in the prevalence of psychological distress by almost all survey items, including disaster-related risk factors, most of which were also associated with increased Prevalence ratios (PRs). Additionally, we found that psychological distress in each evacuation zone was significantly positively associated with the radiation levels in their environment (r = 0.768, p = 0.002). Conclusion The earthquake, tsunami and subsequent nuclear accident likely caused severe psychological distress among residents in the evacuation zone in Fukushima Prefecture. The close association between psychological distress and the radiation levels shows that the nuclear accident seriously influenced the mental health of the residents, which might be exacerbated by increased risk perception. To provide prompt and appropriate support, continued psychosocial intervention for evacuees is strongly recommended.

Positive Coping Up- and Down-Regulates in vitro Cytokine Productions from T Cells Dependent on Stress Levels

Background: Specific coping styles have been shown to modulate stress-induced immune alterations and influence actual health outcomes. This study examined the effects of stressors and coping styles on human T-cell subpopulations and in vitro cytokine production using a cross-sectional design. Methods: Seventy-one men (18–60 years old) were asked to complete a self-administered questionnaire that evaluates quantitative workload, mental demand and coping styles. The numbers of T-cell subpopulations and concentrations of interferon-γ (IFN-γ) and interleukin-4 (IL-4) after stimulation with phytohemaglutinin were measured. Results: Positive and negative coping were negatively related to IL-4 and the number of CD4+ cells, respectively. Interactions between positive coping and mental demand significantly affected the number of CD8+ cells, IFN-γ, IL-4 and the IFN-γ/IL-4 ratio. Among men reporting high mental demand, positive coping was related to increased IFN-γ and IFN-γ/IL-4. Among men reporting low mental demand, positive coping was related to a decreased number of CD8+ cells and lower concentrations of IFN-γ and IL-4. Analyses adjusting for the numbers of CD3+ and CD8+ cells revealed that the interactive effects of positive coping and mental demand on cytokine levels were attributable to the changes in T-cell function rather than the number of T cells. No modulating effect of anxiety on the associations of stressors and coping with immune function was observed. Depressive symptoms slightly, though not significantly, modulated the association of negative coping and the number of CD4+ cells. Conclusions: From the perspective of immunology, optimal stress characteristics were determined by an individual’s coping styles, with positive coping being associated with stress-induced changes in the number of CD8+ cells and in vitro cytokine production from T cells. Our findings suggest that it is important to consider the interactive effects of the complexity of work and the individual coping style in stress management.