Due to the worldwide high number of refugees in recent years, the mental health of different refugee populations has become the focus of many researchers in numerous receiving countries. However, the vast majority of this research focused on the three most common mental disorders depression, anxiety, and PTSD (3, 11, 12). In Germany, the western country with the most accepted recognized refugees, is still a lack of data on SOD among the hosted refugees (51). Particularly Syrians, the largest refugee population in Germany, have surprisingly hardly been considered in studies on somatic symptoms. To the best of our knowledge, this is the first register-based study to report on the patterns of SOD in Syrian refugees with residence permission in Germany. The results of our study highlight the great burden of somatic symptoms among Syrian refugees in Germany and the strong association between this burden with pre- and post-migration factors and with other common mental disorders. The revealed increased medical service utilization among somatically strained Syrian refugees should alert both policy makers and health care providers to this highly vulnerable group.
Health characteristics and health care utilization
In this regard, 85.3% of our study sample had at least one medical visit in the last 12 months, 6.0% had 11 to 20 appointments and 5.2% even had more than 20 appointments. Participants in the high SOD group (PHQ ≥ 10) reported significantly higher medical service utilization than participants in the low SOD group. Although the number of visits to the doctor may be partly attributed to the SOD severity and be an indication of somatization, it must also be taken into consideration that the number of visits per person in Germany is well above the international average. The average German population has 9.9 medical appointments per year, while the international average is at 6.8 visits (52). This may have led to the Syrian refugees adapting to the practices of the German health system. Unfortunately, to our knowledge, such a statistic doesn’t exist for the Syrian health system since an outpatient health insurance is not established so far (53). Of the total sample, 13.8% reported chronic diseases and 25% the regular intake of medication, which may lead to the need of medical treatment. In a study among Syrian refugees in Turkey, 39% of the sample stated living with a chronic illness or disability being associated with the severity of increased SOD (17). In contrast to the high percentage of health care utilization, only 7.8% of the sample admitted to previous treatment of mental disorders. Among the respondents with high SOD, the percentage was a little higher at 10.7%. This could possibly be related to the assumption that refugees prefer to be referred to medical services, rather than to psychiatric institutions, as they have limited knowledge and awareness of mental health or they fear stigmatization by the doctor, their family, or compatriots (54). Language barriers as well as a limited understanding of the German mental health care system may also be reasons for the limited use of these services (14). Given the high proportion of detected mental disorders among this refugee sample in Germany, a gap in mental health treatment becomes apparent at this point.
Prevalence of somatic symptoms and somatic distress
The mean PHQ-15 score in our sample was 6.35 and thus lower than in the Syrian refugee sample in Turkey (M = 8.9) or a sample among internally displaced persons in Ukraine (M = 7.4) but higher than in conflict-affected persons in the Republic of Georgia (M = 5.39) (17, 31, 46). Most frequently, participants reported pain in arms, legs and joints, back pain, and headaches. This is fully consistent with the results of a systematic review among chronic pain in refugees with PTSD (55). Further, almost half of the participants (49.1%) were at least at risk of SOD which is in line with previous studies among SOD in refugees (17, 31). However, one in four respondents of the presented study (24.1%) experienced moderate to severe SOD which is much less than in comparable research using the PHQ-15 in a Syrian refugee sample in Turkey (43%) (17). In contrast, in a study among Kosovar civilian war survivors only 12.9% of participants met the criteria for SOD (56). More similar prevalence rates to our results have been reported in studies of conflict-affected adults in Georgia with 18%, 31% in the Ukraine and a study among refugees recently arrived in Germany with 31% suffering from somatization (15, 31, 46). In the German general population however, the prevalence of somatization at a moderate to severe level is considerably lower, at 9.3% (57). There are many possible explanations for this discrepancy. One explanation may be that yet unknown somatic diseases based on traumatic experiences such as torture or war injuries lead to somatic complaints (14). Another explanation for the cultural differences in SOD attributes the higher somatization prevalence of collectivistic cultures, which include the Arabic countries, to the greater tendency to express psychological distress as somatic sensations which are socially and culturally accepted (58).
As an additional finding, somatically high distressed participants reported significantly more difficulties in working, housekeeping, and interaction with other people than participants with low SOD. That indicates the high impact of SOD on the general well-being and quality of life of those affected.
Comorbidities of somatic distress with other common mental disorders
Besides the detected high somatic distress levels, clinically relevant scores of depression were found in 30.2%, anxiety in 15.5%, and PTSD in 12.1% of the participants. These findings are in line with previous research that has observed high prevalence rates of mental disorders among Syrian refugees, despite the fact that the rates detected in the present study tended to be lower (e.g. 40.2% of depression, 31.8% of anxiety, and 29.9% of PTSD in Tinghög et al. (2017) (59)). A striking finding of our study was the high comorbidity between SOD and the other common mental disorders. Among the participants screened positive for SOD, 75% showed comorbid depression, 46% comorbid anxiety, and 28.6% showed comorbid PTSD. For the comorbidity with depression, this percentage was higher than in a general refugee sample in Germany (44.9%) but much lower for the comorbidity with PTSD (60.3%) (15). No conclusive statement can be made about a comorbid anxiety disorder among refugees with high SOD. To the best of our knowledge, no previous studies among refugees have reported on that. However, there is striking evidence among previous research on the strong association of SOD with depression, PTSD, and anxiety among refugees (17, 31, 60).
Risk factors for increased somatic distress
In our study, increased SOD was significantly associated with all other three captured mental disorders. Besides the strong association with mental disorders, we also found significant correlations of SOD with female gender, higher age, the amount of health care utilization in the past 12 months, the amount of traumatic experiences, and the post-migration stress factors homesickness, intercultural contact stress, and general psychosocial stress. For most of these factors we found similar results in previous research on several refugee populations, including samples of conflict-affected Ukrainians, recently arrived refugees in Germany, traumatized refugees in Switzerland, Kosovar civilian war survivors, and Syrian refugees in Turkey (15, 17, 31, 32, 56). Only information on the connection between SOD and post-migration living difficulties of refugees is widely missing in existing studies.
Furthermore, multiple block wise regression analyses revealed the extent of health care utilization, anxiety symptoms and depression symptoms to be the most robust predictors for the severity of somatic symptoms when adjusted for sociodemographic, migration-specific, and other critical variables. This analysis proved the strong impact of comorbid mental disorders on SOD as their inclusion to the regression model increased the explained variance from 28.6–60.9%. Without the adjustment for mental disorders, female gender, amount of health care utilization, experienced traumatic events, and general psychosocial stress (e.g. financial problems or feeling alone) were shown to be significant predictors of the severity of somatic symptoms. It was striking that the influence of post-migratory general psychosocial stress on SOD was greater than that of traumatic experiences. All predictors have already been found in different samples of refugees and host countries except for the concept of general psychosocial stress (14, 17, 22, 31). Instead, however, parts of this construct, such as bad economic status, have already been identified as risk factors for SOD (31, 46).
At this point, we would like to highlight the identified risk factor of female gender. In our study sample, women experienced significantly higher scores of SOD than men and reported significantly more severely distressing symptoms. In addition, women consulted medical services significantly more often than men and rated their health status as well as their mental health status significantly lower than men did. In this respect, women represent a highly vulnerable group among Syrian refugees and have to be specifically addressed by mental health services.
Strengths, limitations, and implications
A major strength of this study was the register-based approach to assess patterns of SOD. To the best of our knowledge, this was the first study to explore the specific characteristics, co-occurrences, and risk factors of SOD among Syrian refugees in Germany. Especially the inclusion of acculturative stressors represents a rarity in the investigation of SOD in refugee populations. In addition, a broad range of mental disorders was taken into account using well-established, valid instruments, which allowed the calculation of different comorbidities. Another advantage was the investigation of a normal population, not a clinical sample. It should also be highlighted that the questionnaires were presented in the mother tongue and the subjects had a chance to ask questions in their mother tongue.
However, an important limitation of this study was the missing of information on diagnosed diseases or disabilities apart from chronic diseases. A medical examination of the participants would have been even better. The PHQ-15 screening instrument for the severity of somatic symptoms is not suitable to distinguish between symptoms that are physically or psychologically explained (61). In this respect there was no opportunity for a medical explanation of physical symptoms and advances the possibility that our findings overrepresented the true levels of SOD in our study population. Another problem, relating to the PHQ-15 is the different cut-off scores used in previous research for detecting SOD or somatization (e.g. PHQ-15 score ≥ 6, or ≥ 10, or the presence of at least three severely bothering somatic symptoms) (17, 31, 44). This complicated the comparability among study results and should be standardized in the future. The fact that different terminology and definitions exist for the construct measured by the PHQ-15 questionnaire also makes a comparison difficult (e.g. SOD, somatic symptom severity, somatization, somatic symptom burden, somatic symptom disorder, or somatoform disorder).
This study follows a cross-sectional design. Longitudinal data is needed to assess temporal relations between SOD with associated factors, such as acculturative stress. Another limitation of our study relates to the lack of generalizability to the general population of Syrian refugees in Germany, since our entire sample is resident in a specific city in Western Germany. It also has to be mentioned that all data was assessed using self-report questionnaires, which can always be a source of bias.
Despite the limitations and the implications for future research mentioned above, our findings have further implications for German policy as well as for health care practice. Key players in health care systems and among the political authorities need to be aware of the strong links between physical and mental health disorders. Mental health problems underlying physical symptoms can lead to chronicity resulting in social withdrawal, lack of ability to integrate, and increased costs of care (14, 62). Therefore, health care professionals should place importance on the differential diagnosis of medically unexplained physical symptoms in refugees. Instead of only focusing on treating specific somatic symptoms, the possibility of underlying mental disorders, traumatization or post-migration stressors should be considered. This would contribute to minimize the risk of misdiagnoses. Due to specific cultural differences and language difficulties, trained interpreters must be provided for medical examinations. In total, there is strong evidence that culturally sensitive and adapted psychological approaches can help in the treatment of SODs and related mental disorders to increase the individual well-being and to reduce the need for medical service utilization (63).