Though mostly focused on refugees, previous research reported that forced migration serves as a risk factor for poor mental health (Ellis et al. 2008; Kirmayer et al. 2011; Leaman and Gee 2012; van Willigen et al. 2006). Factors related to premigration experiences such as political and religious persecution, rape, torture, famine, war and ethnic conflicts, poverty (Masocha and Simpson 2012; Porter and Haslam 2005; Thomas and Thomas 2004), the loss of family and friends, traumatic experiences during the migration and post-migration experiences including discrimination and restrictive policies (Nakash et al. 2012, 2013; Porter and Haslam 2005) are all likely to play a role in the increased risk of mental ill-health which is reported among refugees and asylum seekers.

In particular, studies have documented an elevated risk of anxiety, depression and post-traumatic stress disorder (PTSD) among asylum seekers and refugees (Burnett and Peel 2001; Fazel et al. 2005; Laban et al. 2004; Tempany 2009). For example, 19 % of the newly arrived adult African asylum seekers in Australia were reported to have mental health problems (Tiong et al. 2006). Prolonged waiting periods for refugee status led to more severe mental distress (Sultan and O’Sullivan 2001) and higher risk of psychopathology (Laban et al. 2004). Similarly, approximately 30 % of asylum seekers who received treatment at the mental health clinic in the Physicians for Human Rights (PHR) Open Clinic for asylum seekers in Israel were diagnosed with PTSD (Lurie 2009). Reesp (2003) suggested that asylum seekers are at high risk for developing psychopathology owing to their limited social support and the uncertainty that accompanies their legal status.

In a meta-analysis examining pre- and postdisplacement factors associated with mental ill-health among refugees and internally displaced persons, Porter and Haslam (2005) identified several factors including age (children and adolescents reported less psychopathology than adults), gender (women have a higher prevalence of depression and PTSD than men) and employment status post-migration (unemployment was associated with worse mental health). In addition, during migration, family structure is often disrupted, and early separation from significant others is common (Chan et al. 2009). Furthermore, a study that examined medical records of refugees from Africa and Asia who participated in the Bellevue Hospital/New York University Program for Survivors of Torture in New York showed that past exposure to multiple traumatic events among participants of the programme was common and was associated with mental ill-health (Chu et al. 2013).

Another post-migration stressor that has received growing attention is detention. In order to deal with the influx of irregular migrants, many countries have adopted a strategy of restrictionism including the establishment of detention centres where asylum seekers are held for undetermined periods of time while their application for refugee status is evaluated (Robjant et al. 2009). Although limited, some research has suggested that a prolonged stay in these centres can contribute to mental ill-health, especially among individuals who experienced traumata before and during migration (Masocha and Simpson 2012). For example, in a 2-year longitudinal study among refugees from Iran and Afghanistan living in Australia, Steel et al. (2011) found that detained refugees had higher baseline and follow-up scores on PTSD scales compared to non-detained refugees. Similarly, Keller et al. (2003) interviewed asylum seekers from Africa, Europe and Asia who lived in the USA and documented that longer periods of detention were associated with more severe symptoms of PTSD at follow-up and suggested that the detention of asylum seekers exacerbates psychological symptoms.

Additionally, asylum seekers, like other migrants, often need to adapt to a new cultural environment that can place them at odds with their heritage culture (Berry 1990), with significant implications for mental health (Heptinstall et al. 2004; Pumariega et al. 2005).

Although some studies indicate the relative lesser vulnerability of adolescent immigrants (e.g. Porter and Haslam 2005), youth migrancy comprises a particularly vulnerable group that is likely to have many risk factors for psychological distress including trauma, loss and social exclusion as a result of prejudice (Beiser et al. 1995). Most of the evidence for psychological distress among migrant youths comes from the post-migration experience in industrialised countries and suggests that behavioural problems, depression and PTSD are common (Beiser et al. 1995; Berman 2001; Bronstein and Montgomery 2011; Kinzie et al. 1986; Lustig et al. 2004; Rousseau 1995).

As with adults, factors related to premigration experiences (e.g. political turmoil and poverty in the country of origin), the process of migration (e.g. the loss of family and friends, traumatic experiences during the migration) and post-migration experiences (e.g. discrimination and restrictive policies) are all likely to play a role in increasing the risk of mental health problems among child and adolescent migrants (Chan et al. 2009; Ellis et al. 2008; Leavey et al. 2004; Pumariega et al. 2005; Stevens and Vollebergh 2008). For example, prevalence rates of psychiatric morbidity as high as 50 % have been found in refugee children from former Yugoslavia and Southeast Asia living in the USA (Sack et al. 1995; Weine et al. 1995) compared to native-born children. Similarly, a meta-analysis comparing the mental health status of refugees from a number of different countries living in six Western host countries found that between 19 % and 54 % of the children and adolescents scored above the clinical cut-off for PTSD, significantly higher than the rates recorded among the youth in the general population in the respective countries (Bronstein and Montgomery 2011).

Although very limited (in number), some research found that migration was also associated with increased engagement in risk behaviours (Romero et al. 2007). For example, Romero et al. (2007) documented that reports of smoking, drinking, drug use and violence were significantly associated with bicultural stress among Latino compared with non-Latino white middle school students in the USA. Viner et al. (2006) further suggested that patterns of risk and protective factors may vary among cultural and ethnic groups and called for research investigating risk and protective factors for risk behaviours among adolescents belonging to minority ethnic groups. In a school-based study of a representative sample in London, Viner et al. (2006) found that the highest rates of co-occurring risk behaviours were observed among adolescent boys of mixed ethnic heritage.

Migrant adolescents are often neglected within the healthcare and educational systems because of their lack of legal status, socio-economic marginalisation, language and cultural barriers and the fact that their parents or guardians are often overwhelmed and unable to care for their needs (UNICEF 2010; Schwartz et al. 2010). In addition, low socio-economic status might play a role in predicting emotional distress among migrant youths. For example, Darwish et al. (2003) found that the low socio-economic status of migrant Turkish parents explained a higher prevalence of behavioural problems of their children compared to Dutch native adolescents.

In the case of migrant and refugee adolescents, findings also support a strong association between perceived discrimination and negative mental health outcomes including depression and PTSD (Ellis et al. 2008, 2010; Te Lindert et al. 2008; Berry et al. 2006; Fisher et al. 2000; Kessler et al. 1999). Migrant youths may also be targets of discrimination for additional reasons such as religious beliefs, immigrant status, ethnicity and/or poverty (Ellis et al. 2010). Berry et al. (2006) further suggested that young people who experience discrimination are more likely to reject the receiving culture.

Gender has also been implicated as a significant factor in predicting mental health status among migrant adolescents as socialisation demands on daughters compared to sons might vary particularly among traditional cultures and thus lead to a differential impact of immigration on emotional distress (Dion and Dion 2001; Vollebergh et al. 2005). For example, Ellis et al. (2010) found that for Somali adolescent girls in the USA, greater cultural identification with the heritage culture was associated with improved mental health, while for Somali adolescent boys, greater identification with the American receiving culture was associated with improved mental health.

In addition, family structure is often disrupted during migration, and early separation from significant caregivers is common (Chan et al. 2009). These migrants are at an even greater risk of developing mental health problems as the turmoil of adolescence is exacerbated by risks associated with immigration and the acculturation processes that affect them during the developmental phase of identity formation (Bronstein and Montgomery 2011; Rumbaut 1994; Stevens and Vollebergh 2008). These young migrants often need to adapt to a new cultural environment that might place them at odds with their heritage culture (Berry 1990), with significant implications for mental health (Heptinstall et al. 2004; Pumariega et al. 2005).

Notably, among adolescents, the relationship between acculturation patterns, gender and mental health problems is further compounded by individual variables such as self-esteem, with research showing a positive association between self-esteem and ethnic identity (Phinney 1989) and a negative association between self-esteem and mental health problems (Oppedal et al. 2004; Smokowski et al. 2010).

To document the exposure of African asylum seekers to traumatic events on their journey to Israel, a survey was conducted at the PHR Open Clinic between the Autumn of 2010 and the Spring of 2012 (Nakash et al. 2014a). We investigated the reported prevalence of exposure to traumatic experiences during migration among a consecutive sample of adult asylum seekers (n = 895 Eritrean, of whom n = 447 women and n = 448 men, and n = 149 Sudanese, of whom n = 18 women and n = 131 men) who sought health services in the Open Clinic. Participants were between 18 and 40 years old.

Upon accessing services at the Open Clinic, participants were interviewed in their native language by a nurse fluent in Tigrinya and Arabic about their experiences during migration. Structured interviews focused on respondents’ experiences in the Sinai desert and included socio-demographic information as well as detailed information about exposure to violence and other traumatic events while in the Sinai desert.

Our findings showed that significantly more male than female Eritrean asylum seekers reported witnessing violence (n = 185, 41.3 %; n = 131, 29.3 %, respectively; χ²(2) = 14.92 p < .001). Over half of the Eritrean men (n = 251, 56.0 %) and a little over a third of the women (n = 156, 34.9 %) reported that they were victims of violence. Exposure to shootings and beatings were the most prevalently reported violent experiences. Significantly more Eritrean men than women reported being shot at (n = 157, 35 %; n = 106, 23.7 %, respectively; χ²(2) = 15.21 p < .001) and beaten (n = 157, 35 %; n = 57, 12.8 %, respectively; χ²(2) = 65.32 p < .001). Significantly more Eritrean women than men reported being sexually assaulted (n = 24, 5.4 %; n = 2, 0.4 %, respectively; χ²(2) = 19.34 p < .001). More than half of the Eritrean men and women reported being deprived of water (n = 229, 51.1 %; n = 243, 54.4 %, respectively; χ²(2) = 1.16 n.s.) and/or food (n = 252, 56.2 %; n = 271, 60.6 %, respectively; χ²(2) = 1.92 n.s.) during their time in the Sinai desert. Approximately half of the male (51.9 %, n = 68) and little less than half of the female (44.4 %, n = 8) Sudanese asylum seekers reported being victims of violence while in the Sinai desert. Shooting was the most prevalent experience of violence reported by Sudanese men and women (n = 62, 47.3 %, and n = 8, 44.4 %, respectively; χ²(2) = 0.32 n.s.). They were shot at, or they witnessed shootings. They were exposed to violence Incl. being shot. Approximately half of the Sudanese men and women reported being deprived of water (n = 71, 54.2 %, and n = 9, 50 %, respectively; χ²(2) = 1.12 n.s.) and/or food (n = 75, 57.3 %, and n = 9, 50 %, respectively; χ²(2) = 0.33 n.s.) during transit. Sexual assault was not reported by the Sudanese, but the very small number of reports among the Eritreans is considered an under-reported rate (see below).

It should be noted that the data in this study were collected only from a specific sample, namely, those who sought medical treatment at the Open Clinic and who may therefore represent a particularly vulnerable or resourceful group. In addition, data were self-reported approximately 1 year after arrival to Israel and may therefore be subject to reporting and recall biases. Many torture survivors, especially rape victims, may have been reluctant to reveal what they had undergone in Sinai (Schubert and Punamäki 2011), thus our data may represent an under-reporting of these experiences. Most importantly, our study included only those who survived the journey. A recent report based on the testimonies of Eritrean asylum seekers who were tortured during and after captivity suggests that during the last 5 years, an estimated 4,000 asylum seekers did not survive the torture camps and journey, losing their lives in the desert (van Reisen et al. 2012).