Vulnerable groups

Despite the above there were important functional challenges for some groups of refugees. As elsewhere, both disease history and current disease treatment were associated with greater psychological distress, emphasising the need for particular support for individuals with physical ailments. This may result partly from a Japanese tendency for somatic presentation of mental distress. ^{Reference Goto and Wilson22} As in other Japanese research loss of family members during mass trauma was associated with distress. ^{Reference Bonanno, Brewin, Kaniasty and La Greca10}

Distress and dysfunctional behaviour were also higher among older refugees. Although older age has been viewed as a protective factor, particularly among those with previous inoculation experiences, ^{Reference Bonanno, Brewin, Kaniasty and La Greca10} the majority of those killed in the tsunami were aged over 60. Compound stresses can rapidly overcome psychological resources, particularly for the frail or disabled. Older Japanese receive less informal support and find it more difficult to turn to health professionals than their younger counterparts. ^{Reference Kwon, Maruyama and Morimoto16} As elsewhere, family employment was a significant predictor of psychological distress and dysfunction, ^{Reference Bonanno, Brewin, Kaniasty and La Greca10,Reference Bonanno, Galea, Bucciarelli and Vlahov12,Reference Nakamura, Kitamura and Someya18} and the stresses of having to find new employment can be particularly onerous jobs for the elderly. ^{Reference Maeda, Oe, Tangawa and Chhem5} Consistent with prior studies in Japan, ^{Reference Fukuda, Morimoto, Mure and Maruyama13} a decline in health activity following mass trauma was associated with increased distress and dysfunctional behaviours. Higher levels of stress levels and greater dysfunction were evident among women, as elsewhere. ^{Reference Bonanno, Galea, Bucciarelli and Vlahov12,Reference Nakamura, Kitamura and Someya18} This may result from their greater coping role following disaster. ^{Reference Liang and Wang9}

Different regions may experience stressors in different ways and suffer varying degrees of community disruption. Number of deaths in an area has been previously related to distress, ^{Reference Matsubayashi, Sawada and Ueda4} but despite lower levels of family deaths ^{Reference Kitamura, Kiyohara and Iwami7} residents from Fukushima reported greater distress than those from Miyagi. Several factors may contribute to this ^{Reference Maeda, Oe, Tangawa and Chhem5} including the uncertainties and confusion associated with the radiation leak ^{Reference Rubin, Amlôt, Wessley and Greenberg23} and the divisive influence of this uncertainty on family relations. ^{Reference Maeda, Oe, Tangawa and Chhem5} Residents from Fukushima also had to deal with arguments over compensation, self-guilt about leaving friends and family, and discrimination in their new location, ^{Reference Shigemura, Tanigawa, Saito and Nomora24} with radiation stigma associated with higher levels of post-traumatic stress in Fukushima. ^{Reference Ben-Ezra, Shigemura, Palgi, Hamama-Raz, Lavenda and Suzuki25} Those living in southern Miyagi reported greater distress and dysfunctional behaviours than those in the north, again despite less household destruction. The northern Miyagi coast has suffered many previous tsunamis, whereas the southern seacoast areas and Fukushima had not witnessed a tsunami for a thousand years. ^{Reference Shibahara6} This may have reduced familiarity with the tsunami threat, and the lack of mountainous terrain for escape in the south may have accentuated anxiety and dysfunctional response.

Social support

As elsewhere, the Japanese prefer to turn for psychological support to families, friends and relatives rather than health professionals. ^{Reference Goto and Wilson22} Social support from family, friends and community members following a disaster can help bolster resilience against multiple stressors ^{Reference Kaniasty, Norris, Neria, Galea and Norris8,Reference Bonanno, Galea, Bucciarelli and Vlahov12,Reference Fukuda, Morimoto, Mure and Maruyama13} and can aid in the development of further social ties and altruism. ^{Reference Matsubayashi, Sawada and Ueda4} Our results are consonant with reports elsewhere showing the negative impact of social network disruption on mental health following an earthquake. ^{Reference Nakamura, Kitamura and Someya18} Support might be of particular importance at key historical points (e.g. following the anniversary of the event, when anxiety may be heightened ^{Reference Goto and Wilson22} ). Particular supporters are likely to provide different forms of support (friends, relatives and spouses provide emotional support; relatives and friends tangible aid). ^{Reference Hayashi and Nishio14}

Overall our data demonstrated the positive impact of household visitors and key emotional supporters on psychological health following disaster. Nevertheless, as other data from the Great Japan earthquake show, supporters themselves may be doubly stressed by their dual role of support provider and survivor. ^{Reference Sakuma, Takahashi, Ueda, Sato, Katsura and Abe26} Japanese values of patience and accepting hardship ^{Reference Lifton27} are also accompanied by an unwillingness to publicly disclose emotions, at least to some. ^{Reference Goto and Wilson22} Notably in our data, some family relations were less able to provide positive support. Having a child or daughter-in-law visit the home was associated with greater sleeplessness, home visits from a daughter-in-law greater morning alcohol use. The negative effects of daughter-in-law visits may reflect a survival disadvantage for Japanese cared for by this relation (the ‘daughter-in-law penalty’), ^{Reference Nishi, Tamiya, Kashiwaga, Takahasi, Sato and Kawachi28} as well as a Confucian sense of shame associated with receiving help from younger generations. This suggests social connections may not always be protective, and that too much emotional disclosure to some can be sometimes damaging. ^{Reference Matsubayashi, Sawada and Ueda4} In univariate analyses, support from a child was related to greater distress and dysfunction but in multivariate analyses controlling for demographics and risk exposure this effect was reversed, suggesting suppressor variables. Indeed, multilevel analysis indicated that the impact of support from a child on distress varied significantly between families when family death, economic situation and visitors to the household were included. This underlines the need for further multilevel modelling of support among potentially vulnerable providers following disasters.

Limitations, implications and future research

We recognise several limitations to our study. Although widely used in Japan, ‘Western’ screening scales (such as the K6) may provide conservative estimates of distress compared with clinical interviews. ^{Reference Goto and Wilson22} As a consequence, such scales may misrepresent relationships between symptoms and daily functioning. Data were self-reported, meaning we cannot always be certain about the identity of the respondent completing the scales and our study was cross-sectional, with no baseline or longer-term outcome measures, limiting our ability to infer causality. For example, although social support may predict decrease psychological distress in the first year after a disaster, it may be the psychological distress that then predicts availability of social support in later years. ^{Reference Kaniasty and Norris29} As is common with large postal surveys, questions were necessarily restricted and offered only a limited range of responses (e.g. on household loss). Data were available on only a limited number of socio-contextual factors and further research could include other variables such as biological markers of illness or more detailed medical histories. One promising area for future research is the mental health consequences of practising the Japanese cultural concept of ‘tsunami tendenko’ – prioritising self-preservation and not stopping to help others following a tsunami. Although this has been attributed to the saving of many lives following the disasters, a failure to help others may contradict the collective priorities of Japanese citizens. ^{Reference Yamori30}

Our findings have a number of implications. First, in focusing on providing economic and housing support governmental agencies often neglect the mental health of survivors. ^{Reference Fukuda, Morimoto, Mure and Maruyama13} However, stressors following a trauma are likely to have a range of societal impacts, including increased rates of sickness absence, ^{Reference Izutzu, Shibuya, Tsutsumi, Konishi and Kawamura31} and somatisation of stress may increase the burden on hospitals following major trauma. Those with a history of illness or present ailments may need particular help from health professionals, and loss of employment is also associated with less resilience post-disaster. ^{Reference Bonanno, Galea, Bucciarelli and Vlahov12} Refugees may benefit from increased opportunities to participate in physical activity. Social support from family and friends is also likely to be important: intervention programmes focusing on vulnerable sections of the community (e.g. age or gender groups) and building on existing community ties are likely to be most efficacious. ^{Reference Matsubayashi, Sawada and Ueda4,Reference Joffe, Rossetto, Solberg and O'Connor32} This may require relocation of families and communities to similar locations to complement existing social support networks. ^{Reference Matsubayashi, Sawada and Ueda4} At the same time, some family relations (particularly the more vulnerable) may be less suitable to provide support and need particular attention following mass trauma.

Regional differences in distress and dysfunction also suggest an urgent need to reduce the uncertainty surrounding the Fukushima incident. Regard must be taken of the distrust towards ‘official’ messages following nuclear leaks, ^{Reference Shigemura, Tanigawa, Saito and Nomora24} with a need to identify trusted expert communicators ahead of any future incidents. ^{Reference Joffe, Rossetto, Solberg and O'Connor32} Particular care needs to be taken with internet coverage, with one study in Western countries showing associations between internet use and sleep disturbances and subclinical post-traumatic stress following the Fukushima disaster. ^{Reference Bui, Rodgers, Herbert, Franko, Simon and Birmes33}

A growing increase in natural disasters worldwide makes it essential to understand both tangible and emotional determinants of post-disaster psychological functioning. Our data from refugees of the Japanese tsunami show no simple relationship between housing loss and distress and functioning, with those who reported house collapse actually less likely to report at least one dysfunctional behaviour. Instead our findings emphasise the importance of pre-existing illness and family and community histories – and in particular emotional support provision – in aiding resilience and recovery. At the same time multilevel analysis suggests that not all supporters are associated with reduced psychological distress, and the efficacy of such support is likely to vary across families. Findings also suggest the need for normalising routines among those whose physical activity was disrupted by the disasters, and regional variations in response underline the need to reduce uncertainty following incidents such as a nuclear leak, confronting myths and stigma associated with those from affected areas. Recognising these factors is likely to be important in tailoring community interventions both during and following crises.