Key findings
To the best of our knowledge, this is one of the largest studies done on the mental health of trafficked persons so far. Our findings demonstrated a high frequency of probable anxiety, depression, and PTSD symptoms among Ethiopian returnees. Violence was associated with anxiety and PTSD; it was also a significant mediator variable between these two mental health problems and most of the exogenous variables in the model that were either socio-economic or trafficking exposures. However, for depression we saw only direct effects for most of the exogenous variables in the model.
In this study, about half of the returnees had symptom of anxiety, almost one-third showed PTSD symptoms, and over half of them reported depression. Our estimate of general anxiety disorder was much greater than the prevalence of anxiety disorder for the general population in Ethiopian (3.3%) [
27] and that of the Syrian post war refugees (31.3%) [
28], but comparable with some studies conducted on trafficked persons [
11,
29]. Of course, high variation in the magnitude of anxiety among trafficked persons has been reported in the literature, ranging from about 6% [
15] to 90% [
14]; similar variations were observed for depression and PTSD. The high rate of mental health symptoms identified at the end of the trafficking period could be explained by the extreme forms of abusive conditions respondents experienced during the trafficking periods that usually involve strict control, violence (physical, sexual, and psychological), torture (that could happen sometimes to get money from the family of trafficking victims), intimidations, deprivations and social stigma [
30,
31]. Pre-trafficking conditions like personality factors, childhood conditions, and socio-economic status could also contribute to the high level of mental health problems [
32].
The high heterogeneity of the prevalence of the mental health symptoms reported by previous studies could also be related with the variation in these predisposing factors among the respective study populations considered. Moreover, the time point during the trafficking process at which the assessment of symptoms was conducted also is likely to be another factor influencing results across studies. For instance, our study assessed anxiety and depression during the last 2 weeks prior to the interview at the port of return to Ethiopia, and PTSD during the last 1 month of the trafficking period. As some of the returnees were freed from the trafficking condition close to the date of interview, the rate of symptoms could be higher than in studies conducted long after the integration/reintegration or late during the post-trafficking period [
29].
Mental health is a complex phenomenon [
33] and our study addressed this situation by exploring and analyzing concomitantly the mental health outcome variables, violence experienced during trafficking [
12], and other potential predisposing factors (socio-demographic and factors representing situations during trafficking) [
11,
12,
16,
29]. Thus, this study is also unique in that the complex network of relationships among the factors that affect mental health of trafficked persons was also described by employing appropriate statistical technique.
Violence (physical, sexual, or both) experienced during trafficking was positively associated with anxiety and PTSD and this is of course in line with other reports [
12,
34]. The abuse, intimidation, and mistreatment of migrants could result in stress that may in turn result in various mental health problems including anxiety. As a mediator variable, violence was positively associated with female sex, history of detention, and time in trafficking situation but negatively with social support.
The association between history of detention and violence could probably be related with the extra force used by detainers or the mistreatment during their detention at the transit or destination countries [
35]. Time in trafficking situation is also positively associated with violence and this may not be surprising because as the duration of time spent in trafficking situation increases, the risk of experiencing violence also increases [
14]. The negative association, i.e. a protective effect of social support before departure and violence could be probably explained by the support from families or others from the social network which might have continued even during the hard times after departure. For example, sometimes traffickers torture their victims to obtain money from their families, and in this extremely stressful situation, strong social support may play an important role to reduce the adverse influence of this serious human rights violation [
36].
Socio-demographic variables (sex and social support) and trafficking related variables (restricted freedom, time in trafficking, and history of detention) predicted directly and independently both anxiety and depression; except restricted freedom, all of these variables were also indirect predictors of anxiety through violence as mediator. Studies showed that females are disproportionately affected by common mental disorders than males [
37‐
39] due to gender specific risk factors like gender-based violence, low socio-economic status, and constant responsibility of caring for others [
40,
41]. The situation could be worsening for females under trafficking condition, a severe form of violence. The high prevalence of physical and sexual violence to which females are exposed [
29] and the correspondingly high rate of PTSD following such violence renders trafficked females the largest single group of people affected by this disorder.
Restricted freedom of movement has been shown to be an independent predictor of anxiety, depression [
11,
12], and PTSD [
11], probably linked to the stressful conditions such as strict control exerted over trafficked persons that limit their right to behave and move freely. Returnees who had better social support also had a reduced risk of developing symptoms of mental health. As the history of detention encountered during trafficking period increases, the risk of developing anxiety was also high. Some results supporting our findings have also been reported from women detained by police in Vietnam [
34].
Interestingly, individuals who had stayed longer in trafficking situations were less likely to report symptoms of anxiety and depression during the last 2 weeks of their trafficking period. This contradicts with a finding from a study conducted among females in seven post-trafficking support services that reported a positive association between time in trafficking and anxiety or depression [
16]. Of course, there are also studies reported inconclusive findings for anxiety, depression and PTSD [
16,
34] and mental health disorders [
15]. Here the association was between the time spent in trafficking situation and the presence of symptoms within the last 2 weeks of the respective trafficking period, but not with the presence of symptoms in the trafficking period overall. It is unclear whether adaptation to the exploitive conditions plays a role in this context. For example, the initial phases of trafficking could be particularly tragic and stressful for newly trafficked persons until they adapt—to some extent—to cultural and social disparities and other circumstances that could influence mental health. Individuals who developed symptoms of mental health problems early-on could recover from it during the trafficking period even without proper treatment [
42]; and this could result in a negative association with time spent in trafficking situation. However, differences between studied populations in terms of sex, time covered by the interview questions etc. need to be considered when interpreting findings from this and other studies [
16].
The presence of PTSD during the past 1 month was associated with socio-demographic variables (positively with female sex and negatively with wealth index) and trafficking exposures (positively for both restricted freedom and history of detention). Both restricted freedom of movement during traveling and history of detention by security personnel create stressful conditions increasing the frequency of PTSD, as our study shows, and again this may be true particularly for the disadvantaged group of women and girls [
39,
40]. The household wealth index was negatively associated with PTSD. One possible explanation is that the financial and material capacity of families is to some extent protective against the strict control of traffickers [
36] and eventually against subsequent PTSD symptoms.
Strengths and limitations of the study
The current study used standardized questionnaire, and data were collected by trained and experienced field workers with close and supportive supervisions. For ethical reasons, participants who were severely mentally ill and unable to give information were excluded from the study. However, as the number of excluded persons was small, this might not substantially affect the magnitude and direction of effects. Generally, respondents were informed about the importance of the study and the confidentiality of personal data to gain the trust of respondents and minimize the nonresponse rate. As the assessment of mental illnesses was conducted when respondents just entering into Ethiopia from abroad, the PTSD assessed might not actually reflect the stress disorder during post-trafficking or traumatic period but rather acute stress disorder during the traumatic or trafficking period. Of course, this could be true for individuals who escape an exploitive condition and returned within a time shorter than 1 month as PCL-C captures mental health symptoms during the past 1 month only. The other limitation of the study is the use of assessment tools of mental illness but not diagnostic tools. A further limitation is the use of mental health assessment tools that have not been tested in specific populations such as trafficked persons. However, the validity and reliability of these tools were checked in the general population of culturally diversified contexts. We also found that the reliability of the scales used were high for all the three tools. On the other hand, as the study included only returnees, the findings might not be generalizable to those trafficked Ethiopians who are still outside the country, possibly in a continuous trafficking situation. However, we assume that our results are informative and valid with respect to the general population of returnees who experienced trafficking. Overall this is a highly sensitive research topic and population where high quality empirical research is a particular challenge.