Aims:  Hikikomori is a form of social withdrawal among those who retreat from social interaction for protracted periods of time. This study examines family‐related childhood factors for hikikomori using the retrospective data derived from a population‐based survey.Methods:  We derived data from World Mental Health Survey Japan. The subjects of this study were community residents aged 20–49 years (n = 708). Multiple logistic regression was applied to examine the association between the lifetime experience of hikikomori and childhood family environment, adjusting for sex, age, and respondents' history of common mental disorders.Results:  Father's high educational level (odds ratio [OR] = 6.0, 95% confidence interval [CI] = 1.6–22.9), mother's common mental disorders (OR = 5.9, 95%CI = 1.1–33.3), and mother's panic disorders (OR = 6.6, 95%CI = 1.1–39.1) were significantly and positively associated with hikikomori after controlling for respondents' sex, age, and history of mental disorders.Conclusions:  Our findings suggest that hikikomori cases are more likely to occur in families where the parents have high levels of education. Maternal panic disorder may be another risk factor for children to develop hikikomori.

Objectives: The present study aims to examine sociodemographic correlates and comorbid mental disorders among adult with autism spectrum disorders (ASD) and attention deficit hyperactivity disorders (ADHD) using the national representative data of Japan. Methods: Analysis was conducted on the cross-sectional data derived from the World Mental Health Japan Survey 2, whose participants were community residents aged 20–75 years old. Multiple logistic regression was conducted on the data of those who were assessed for adult ASD (N = 2227) and ADHD (N = 2297). The association of adult ASD/ADHD with sociodemographics, mood disorders, anxiety disorders, substance use disorders, suicide ideation, hikikomori (social withdrawal), and internet addiction was examined, adjusting for sex and age. Gender difference in the association was also assessed based on the interaction terms of sex. Results: None of the sociodemographics characteristics were significantly associated with adult ASD/ADHD. ADHD had increased risks for a variety of mental disorders, having the highest odds ratios for social phobia. However, a significant positive association was limited to social phobia and to drug abuse and dependence among those with adult ASD. Hikikomori and internet addiction were positively associated with ASD/ADHD, while suicide ideation was only associated with ADHD. Women with ADHD were more likely to have any one of mental disorders, as well as alcohol abuse and dependence, compared to men with ADHD. Conclusions: Adults with ASD/ADHD in Japan had increased mental health needs. The specific needs of women with ADHD should be also considered in future clinical work and research.

Little scientific evidence exists on ways to decrease the psychological stress experienced by disaster responders, or how to maintain and improve their mental health. In an effort to grasp the current state of research, we examined research papers, agency reports, the manuals of aid organisations, and educational materials, in both English and Japanese. Using MEDLINE, Ichushi-Web (Japanese search engine), Google Scholar, websites of the United Nations agencies, and the database of the Grants System for Japan’s Ministry of Health, Labour, and Welfare, 71 pertinent materials were identified, 49 of which were analysed. As a result, 55 actions were extracted that could potentially protect and improve the mental health of disaster responders, leading to specific recommendations. These include (1) during the pre-activity phase, enabling responders to anticipate stressful situations at a disaster site and preparing them to monitor their stress level; (2) during the activity phase, engaging in preventive measures against on-site stress; (3) using external professional support when the level of stress is excessive; and (4) after the disaster response, getting back to routines, sharing of experiences, and long-term follow-up. Our results highlighted the need to offer psychological support to disaster responders throughout the various phases of their duties.

The coronavirus disease 2019 (COVID-19) has profoundly affected the psychological well-being of foreign residents. This study examines stress, anxiety, and depression levels in Chinese residents in Japan during the COVID-19 pandemic. It identifies risk factors and the roles of disaster preparedness and social support. An online survey among Chinese residents in Japan was conducted from 22 June to 14 July 2020. The Depression, Anxiety and Stress Scale, Disaster Preparedness for Resilience Checklist, and Social Support Rate Scale were used to measure psychological symptoms. Multivariable linear regressions identified the risk factors and positive effects of disaster preparedness and social support. Of the total 497 participants, 45.3%, 66.6%, and 54.3% reported severe stress, anxiety, and depressive symptoms, respectively. People with a lower level of education, a higher level of economic influence, the presence of COVID-19 symptoms, and confirmed or suspected family or friends in China were associated with higher levels of stress, anxiety, and depression. This study, to the best of our knowledge, is the first survey to reveal the protective role of disaster preparedness in reducing psychological symptoms during the pandemic. It offers unique data for further research on how to promote the mental health of vulnerable populations including foreign residents.

Worry about radiation persists long after nuclear power plant accidents. Young age, low socioeconomic status, being married, and disaster-related experiences are known to be associated with greater worry about radiation. This study explored the duration of the effects of these risk factors on worry about radiation after the 2011 Fukushima nuclear power plant accident, using the longitudinal data of randomly sampled non-evacuee community residents who were followed five to ten years after the accident. Questionnaire surveys were conducted five times with 1825 respondents (37.2% of the 4900 initial targets). We examined the interaction of time and risk factors of worry about radiation using a mixed model. Fear or anxiety immediately after the accident had effects on worry about radiation that continued even after 10 years, though it slightly attenuated with time. Family problems stemming from the disaster retained their effects. While direct damage and evacuation experience were significantly associated with worry about radiation in the early phase, their effects diminished and became non-significant during the study period. Being under the age of 65, having low educational attainment, and being married were significantly associated with worry about radiation, although the association with age weakened over time. Individuals who experience intense fear or anxiety post-nuclear power plant accidents or disaster-related family problems may need continuous monitoring for their worry about radiation even 10 years after such accidents.