The investigation strongly suggests that children seeking asylum develop psychiatric symptoms as a consequence of protracted stay at asylum centres and multiple relocations. These effects on asylum-seeking children's mental health have not been estimated before, but the results confirm those of previous studies of the association between post-migration environmental stressors and asylum-seeking children's mental health [1, 3, 11]. Most likely a complex interplay between several factors explains our results, and their unique importance is still not fully known.
Furthermore, the children have notably worse mental health in comparison to a European background population where the proportion of children with mental difficulties is approximately 10% [22, 32]. Similar differences have been found in former studies with indigenous European children compared to asylum and refugee children in which SDQ was used [33, 34].
Strengths and limitations of the study design
The strengths of this study lie in the relatively high number of study subjects and the low non-response rate, which is rare when dealing with this vulnerable and fluctuating population. Additionally, the use of a validated and widely used screening instrument must be considered a strength. The most important limitations of the present study include the cross-sectional design and the fact that the children were not subject to a clinical investigation.
As the current study had a cross-sectional design, the observed associations between the included variables are not necessarily causal. Nonetheless, there is overwhelming evidence that the process of seeking asylum is both directly and indirectly a stressful and disturbing experience [3, 7–9, 12, 15, 35], and the longer the time spent within the asylum system the higher the risk of developing mental disorder among adults [7–9, 13]. Although, former studies on this subject have been carried out among a small number of children, they still show similar findings [3, 11]. In addition, evidence exists that families' stressful experiences and parental mental health – also during post-migration – have a harmful influence on the children [1, 3, 14, 36]. Thus, the causal interpretation of an effect of the length of stay at the asylum centres on the children's mental health is likely; however, the present estimated odds ratio values must be interpreted cautiously.
In quantifying the outcome measure of mental difficulties, there is a possibility of it being influenced by a number of uncertainties. Firstly, the children were not subject to an individual psychiatric or psychological investigation. In order to assess validity of our screening, it would have been relevant to let the children with high scores undergo an individual psychiatric investigation but because of anonymity that was not possible. Conversely, the SDQ is an internationally validated screening tool with a sensitivity of 63–85% and a specificity of 80–95% as well as positive and negative predictive values of 53–74% and 89–96%, respectively [23, 24]. Yet, there are several ways to handle the SDQ-scores and the way chosen makes some difference regarding the estimated outcomes [37]. On the background of the present study, we cannot estimate the occurrence of psychiatric disorder with certainty for which reason the strength of the association between the organisational factors and the mental health might be somewhat imprecise.
Secondly, the assistance of a researcher during the children's responses may have influenced the children's replies towards both under- and overrating of symptoms due to, for instance, reluctance to expose his or her own vulnerability or an interest in gaining sympathy. Thirdly, linguistic misunderstandings may have occurred in the children's replies to the questionnaires. However, this problem seems significantly reduced by the fact that the researcher took steps to ensure that the children understood each single question and answer category by dialogue and exemplification as well as employment of an interpreter in special cases. Furthermore, the problem was reduced by the use of different data sources. Nevertheless, the 11–16-year-old children reported a considerably higher number of symptoms relative to the teachers' replies. The children's high self-report could reflect an actual overrating arising from a wish to strengthen own asylum case by appearing mentally affected; however, it could also reflect that the 11–16-year-olds had severe mental problems that were far more common than their teachers realised. The same pattern has been seen in former investigations of children in the general population [38]. Potential language barriers limiting the teachers' observations were unlikely as the teachers completed the SDQs only for children who they knew well, implying that the children spoke reasonable Danish and had not arrived very recently. Fourthly, the use of two respondents in itself implies casting a wider net. At least with the standard cut-off scores used here, the result is that more children were seen, rightly or wrongly, as having mental difficulties. Hence, when combining teachers' and children's responses we may have overestimated the true prevalence of mental ill-health.
Factors not investigated
For a large part of the children, the measure of length of stay in the Danish asylum system represents a minimum time of risk since neither time spent during the journey to Denmark was recorded nor the time spent outside the formal asylum system. This would be the case if the child had gone into hiding for some periods or had been applying for asylum in other countries. Number of relocations embodies a minimum estimate for the same reasons. These periods have an impact on the absolute exposure of traumatic events, which can be a contributing factor to the high level of mental illness found among the children [1, 5]. The high level of mental illness is not necessarily a result of the duration of stay in Denmark, but the differences found in this study between the children who had been asylum-seeking one year or less and one year or more, respectively, are presumably true.
It is important to consider whether there might be any differences between the two groups of children (those who have stayed within the asylum system relatively briefly vs. longer) which could explain the differences in their mental health. This matter seems implausible as 1) country of origin was not found to be a significant confounder, 2) the children in question predominantly came from war-torn countries, both those who had been asylum-seeking for years (for instance children from former Yugoslavia) and those who had recently arrived (for instance from Chechnya), 3) the adjacent assumption that resourceful families who are less traumatized are more likely not to continue the asylum process is counteracted by the criteria for obtaining asylum in Denmark which are based on the UN Refugee Convention as well as other international conventions to which Denmark must acceded [19].
Although several factors related to conditions in Denmark were assessed in this study, many other factors were not addressed, such as parental mental health and number of traumatic experiences. Other studies have shown that refugee and asylum-seeking children develop mental illness in response to their parents being functionally impaired because of depression, anxiety, PTSD, or other mental problems relating to the stresses due to the asylum process [1, 3, 14, 36]. Thus, these unexplored variables may have helped to explain some of the associations found.
Generalizability
The overall response rate was 95%. Beyond that, a drop-out analysis showed no deviation of the various background variables between those participating and those not participating. The study population must therefore be assumed to be representative of the present children seeking asylum in Denmark. The existing asylum population in Denmark is characterised by long duration of stay and many relocations at the asylum centres.
Implication of asylum politics
Long duration of stay at asylum centres seems to have an adverse effect on the children's mental health. Even though some of the children might be traumatised when they arrive in Denmark, it appears that the time of stay in the asylum system may harm their mental health even more. These findings have implications for both the national and international asylum politics and they underline the importance of scientific research to support observations of health professionals and social caretakers within this field [6, 11]. To meet our ethical responsibility, we need to voice the words of the unheard by documenting the consequences of the current asylum politics on child mental health. Former studies suggest that a combination of parental, child, and environmental factors constitute the risk factors of child mental illness [1]. As the recipient countries have control of what conditions they offer children seeking asylum, they should seek to minimise the environmental risk factors. Children seeking asylum are among the most vulnerable in our societies, and it is critical that the asylum systems in Western host countries seek to protect children in accordance with the Convention of the Rights of the Child and other international rights documents.