The Fukushima Health Management Survey (FHMS) was established in response to the Fukushima Daiichi Nuclear Power Plant accident on March 11, 2011. The primary objectives of the study are to monitor residents’ long-term health and promote their future well-being, and to determine the health effects of long-term low-dose radiation exposure. This special issue summarizes the results and current status of the FHMS and discusses the challenges and future directions of the FHMS. The FHMS, a cohort study of all people who were residents in Fukushima Prefecture at the time of the accident, consists of a Basic Survey, Thyroid Ultrasound Examination, Comprehensive Health Check, Mental Health and Lifestyle Survey, and Pregnancy and Birth Survey. The radiation exposure was estimated based on the behavioral records examined using the Basic Survey. Although the response rate was low in the Basic Survey, the representativeness of the radiation exposure data was confirmed using additional surveys. There appears to be no relationship between the radiation exposure and risk of thyroid cancer, although more thyroid cancer cases were detected than initially expected. The ongoing Comprehensive Health Check and Mental Health and Lifestyle Survey have provided evidence of worsening physical and mental health status. The Pregnancy and Birth Survey showed rates of preterm delivery, low birth weight, and congenital abnormalities similar to the national average. Considering the above evidence, the Fukushima Prefectural Government decided to end the Pregnancy and Birth Survey at the end of March 2021, as recommended by the Prefectural Oversight Committee. The framework of the FHMS has not changed, but the FHMS needs to adapt according to the survey results and the changing needs of the eligible residents and municipalities.

This review aims to provide a comprehensive overview of the current literature on the drug design, development, and therapy of lurasidone for the treatment of schizophrenia. Lurasidone has antagonistic effects on the dopamine D₂, 5-hydroxytryptamine (5-HT)_2A, and 5-HT₇ receptors and a partial agonistic effect on the 5-HT_1A receptor with low affinities for muscarinic M₁, histamine H₁, and a₁ adrenergic receptors. The receptor-binding profile of lurasidone is thought to be associated with fewer side effects such as anticholinergic effects, lipid abnormalities, hyperglycemia, and weight gain. Behavioral pharmacological studies have demonstrated that lurasidone exerts anxiolytic and antidepressive effects and improves cognitive function, which are associated with the modulation of 5-HT₇ and 5-HT_1A receptors. Literature search using PubMed was performed to find published studies of randomized controlled trials and recent meta-analyses regarding efficacy and safety, particularly metabolic side effects of lurasidone in schizophrenia. In short-term studies, the results of randomized placebo-controlled trials and meta-analyses have suggested that lurasidone was superior to placebo in improving total psychopathology, positive symptoms, negative symptoms, and general psychopathology in patients with acute schizophrenia. Regarding safety, lurasidone had minimal metabolic side effects, and was identified as one of the drugs with the most benign profiles for metabolic side effects. Long-term trials revealed that lurasidone had the preventive effects on relapse, with minimal effects on weight gain and other metabolic side effects. Furthermore, lurasidone improves cognitive and functional performance of patients with schizophrenia, especially in long-term treatment. Patients with schizophrenia require long-term treatment with antipsychotics for relapse prevention; thus, minimizing weight gain and other side effects is crucial. Lurasidone is suitable as one of the first-line antipsychotic drugs in the acute phase, and a switching strategy should be considered during the maintenance phase, to balance efficacy and adverse effects and achieve favorable outcomes in the long-term course of schizophrenia.

Predictive factors including risk perception for mid-term mental health after a nuclear disaster remain unknown. The purpose of this study was to examine the association between perceived radiation risk and other factors at baseline and mid-term mental health after the Fukushima Daiichi nuclear disaster of 2011 in Japan. A mail-based questionnaire survey was conducted in January 2012 and January 2013. Mental health status was assessed using the K6 scale. Psychological distress over the 2-year period was categorized into the following four groups: chronic, recovered, resistant, or worsened. Most participants (80.3%) were resistant to the disaster. A positive association was found between the radiation risk perception regarding immediate effects and the worsened group in women. Baseline post-traumatic stress disorder (PTSD) or a history of psychiatric disease predicted being in the chronic or worsened group in mid-term course. These results suggest that evacuees who believed that their health was substantially affected by the nuclear disaster were at an increased risk of having poor mid-term mental health in women. Careful assessment of risk perception after a nuclear disaster, including the presence of PTSD or a history of psychiatric disease, is needed for appropriate interventions.

A Mental Health and Lifestyle Survey (MHLS) has been conducted yearly as part of the Fukushima Health Management Survey since 2012, in order to monitor different health issues related to long-term evacuation of affected people after the 2011 Fukushima disaster. This survey is a mail-based one of nearly 210,000 affected people living in the evacuation zone at the time of the disaster. Another purpose of the MHLS is to provide efficient interventions by telephone based on the results of the survey. Significant findings contributing to understanding of non-radiological health effects caused by long-term evacuation were obtained from the MHLS, directly connecting to telephone-based interventions for over 3,000 respondents per year. In this article, the mental health outcomes of the MHLS, including depressive symptoms and posttraumatic responses, are reviewed, and the usefulness of telephone-based interventions is discussed. The evidence showed that, despite improvement of core mental health outcomes, the prevalence of respondents at high risk of some psychiatric problems remained high compared to that among the general population in Japan. In particular, several mental health consequences of respondents staying outside of Fukushima Prefecture were higher than those staying inside Fukushima. Along with further efforts to increase the response rate, we need to continue and modify the MHLS to meet the requirements of the affected people and communities.

The longitudinal posttraumatic stress responses and resilient factors after the Fukushima Daiichi Nuclear Power Plant are yet unknown. Here we attempted to quantify the patterns of the course of posttraumatic stress disorder (PTSD) symptoms and we explored the factors associated with psychological recovery. The subjects were 12 371 residents in the municipalities categorized as the forced evacuated area. We categorized the subjects’ PTSD symptoms into 4 groups: Chronic, Resistant, Recovered, and Non-recovered. We applied a logistic regression to clarify the factors related to psychological recovery. We observed that laughter showed significant odds ratio in the Recovered group and the Resistant group. Meanwhile, elderly residents and those with poor living circumstances showed significant odds ratios for the Recovered group and the Resistant group. Laughter in daily life was associated with the psychological health in the evacuation area.

The Taq1A polymorphism in the dopamine D2 receptor (DRD2) gene could be related to the response to antipsychotics. We examined the effects of the Taq1A polymorphism on the plasma monoamine metabolites during the treatment of schizophrenia with aripiprazole, a DRD2 partial agonist. Thirty Japanese patients with schizophrenia were treated with aripiprazole for 6 weeks. We measured plasma levels of homovanillic acid (pHVA) and 3-methoxy-4hydroxyphenylglycol (pMHPG) before and after treatment. The Taq1A polymorphism was genotyped with polymerase chain reaction. Aripiprazole improved the acute symptoms of schizophrenia and decreased pHVA in responders (P = 0.023) but not in nonresponders (P = 0.28). Although A1 allele carriers showed a tendency to respond to aripiprazole (61.5%) compared to A1 allele noncarriers (29.4%) (P = 0.078), there was not statistically significant difference in the response between the 2 genotype groups. There were significant effect for response (P = 0.013) and genotype × response interaction (P = 0.043) on the change of pHVA. The changes of pHVA differ between responders and nonresponders in A1 allele carriers but not in A1 allele noncarriers. There were no genotype or response effects or genotype × response interaction on the changes of the plasma levels of 3-methoxy-4hydroxyphenylglycol. Our preliminary results suggest that Taq1A polymorphism may be partly associated with changes in pHVA during acute schizophrenia.