Abstract
Background:
Challenges of migration, particularly concerning the process of acculturation are associated with an increased risk of mental illness. Vietnamese migrants constitute the largest Southeast Asian migrant group in Germany, yet there is no data on the relationship between the mental health status and acculturation among this population.
Aims:
Therefore, the present study examines the relationship between two well-established dimensions of acculturation, that is, dominant society immersion (DSI) and ethnic society immersion (ESI), the four resulting acculturation strategies (integration, assimilation, separation and marginalization), and severity of depression.
Methods:
A sample of N = 113 first-generation Vietnamese outpatients from a psychiatric outpatient clinic for Vietnamese migrants in Germany was studied regarding their self-reported depressive symptoms (Beck Depression Inventory-II (BDI-II)) and acculturation (Stephenson Multigroup Acculturation Scale (SMAS)).
Results:
Consistent with the hypotheses, patients reported less severe depressive symptoms, when they reported higher orientation toward the German and the Vietnamese society. Moreover, the results showed that integrated patients reported a lower severity of depression compared to marginalized patients, who reported the highest severity of depression.
Conclusions:
The findings indicate that among a sample of first-generation Vietnamese patients with depression, an orientation to both, the mainstream society and one’s heritage society might serve as a potential resource. The rejection of any orientation to any society is associated with an increased risk for depression.
Introduction
Worldwide migration has not only increasingly become an issue in modern societies but also regarding national healthcare systems (Whiteford et al., 2013). The resulting interconnectedness of people, societies and cultures continually challenges researchers to achieve a better understanding of social phenomena such as modes of migration and the adequate psychosocial and mental health care of migrants (e.g. Bhugra, 2004). In this field of research, the concept of acculturation is a framework shedding light on the numerous processes underlying migration (Berry, 1997, 2005). Some studies show that acculturation is linked with mental health outcomes (Gupta, Leong, Valentine, & Canada, 2013; Yoon et al., 2013).
Acculturation
The anthropologists Robert Redfield, Linton, and Herskovits (1936) proposed one of the first definitions of acculturation as ‘those phenomena which result when groups of individuals having different cultures come into continuous first-hand contact, with subsequent changes in the original cultural patterns of either or both groups’. The Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5) (American Psychiatric Association, 2013) defines culture as ‘systems of knowledge, concepts, rules, and practices that are learned and transmitted across generations. Culture includes language, religion, and spirituality, family structures, life-cycle stages, rituals customs, as well as moral and legal systems’. Early research conceptualized acculturation mainly through unidimensional approaches. These assume that one can either immerse into the mainstream society (dominant society immersion (DSI) – for example, adopting attitudes, behaviors) or retain the characteristics of the heritage society (ethnic society immersion (ESI) – for example, cultural traditions, speaking the native language) (Sam, 2006). A unidimensional approach, however, often fails to recognize the complex, dynamic processes underlying acculturation. In response, a revised, bi-dimensional approach allows for the independence of both cultural orientations, meaning that individuals may immerse in the mainstream society while retaining cultural customs of their heritage society (Ryder, Alden, & Paulhus, 2000).
Berry’s bi-dimensional conceptualization has been most prominent and widely investigated (e.g. Berry, Phinney, Sam, & Vedder, 2006). According to this framework, acculturating individuals have to deal with two central issues. First, they have to consider how important it is to maintain the cultural identity of their heritage society. Second, they have to decide whether they are willing to participate in the mainstream society. The individual attitudes regarding these two aspects result in four possible acculturation strategies: integration, assimilation, separation and marginalization. Integration describes both the participation in the mainstream society and the maintenance of the heritage society. Assimilation entails the involvement in the mainstream society, but the rejection of the heritage society. Separation postulates withdrawal from the mainstream society but maintenance of the heritage society. Marginalization involves a lack of participation in either the mainstream society or the heritage society (Berry, 1997). In an international study, Berry et al. (2006) reported empirical data supporting the postulated four strategies. The authors conducted the study with a population of immigrant youth from 26 different cultural backgrounds who had settled in 13 countries and concluded that integration was associated with the best psychological and sociocultural outcomes (Berry et al., 2006).
Acculturation and mental health among Asian migrants
Increasing migration of people from Asian societies as well as reported cultural differences in symptom presentation has raised researchers’ interest in migrants mental health status (Hahn et al., 2016; Kirmayer, 1989). Findings in acculturation and mental health outcomes produced mixed results. Some studies suggested an inverse relationship between an adoption of the mainstream society and psychopathology (e.g. Nguyen & Peterson, 1993). However, a meta-analysis by Gupta and colleagues (2013) demonstrated that an increased orientation toward the mainstream society was associated with depressive symptoms among Asian Americans, while the relationship between retaining the heritage society and depression was not significant.
Regarding acculturation strategies, integration has been associated with a lower risk of depression (e.g. Ince et al., 2014). Another study showed that marginalized Korean immigrant women reported significantly higher depression scores than women with other acculturative strategies. The authors concluded that the absence of orientation toward both the mainstream and heritage society might be a risk factor for depression (Choi, Miller, & Wilbur, 2009). Nevertheless, a majority of studies examining people from different Asian backgrounds were conducted in Anglo-Saxon countries and often focused on Asian adolescents rather than on first-generation migrants (Choi, He, & Harachi, 2008; Hilario, Vo, Johnson, & Saewyc, 2014; Kwak & Berry, 2001). In light of today’s growing cultural interweavement, an investigation of a large Asian migrant group living in European societies is necessary.
There are three distinct migration pathways from Vietnam to Germany. After the end of the Vietnam War in 1975, thousands of South Vietnamese people fled the country by boats. About 40,000 of these refugees, also referred to as ‘Boat people’, were granted political asylum in the Federal Republic of Germany (FRG). At the same time, the German Democratic Republic (GDR) recruited about 80,000 guest workers from North Vietnam (Hüwelmeier, 2013). The third ongoing migration flow proceeds since 1990 and includes Vietnamese people from former Eastern bloc countries as well as people from Vietnam. Today, about 176,000 individuals with a Vietnamese migration background live in Germany, which makes them the largest Southeast Asian migrant population in Germany (Federal Office of Statistics of Germany, 2015).
Present study
Although Vietnamese migrants are the largest Southeast Asian population in Germany, mental health care utilization among this population so far has been reported to be minimal. Our clinical assessments show that 46% of patients had severe depressive symptoms with a Hamilton Score over 23 points, total average 19.6 points (HRSD; Hamilton, 1960) at the time of the first consultation and reported an average duration of untreated illness of more than 3 years (Ta et al., 2015). To improve mental health services for Vietnamese migrants, a better understanding of underlying processes of migration and acculturation is necessary. Accordingly, the present study contains two parts. The first part tested the hypothesis that higher orientation toward the mainstream society and heritage society is associated with lower depression severity among a sample of Vietnamese outpatients in Germany. The second part of this study aims to answer the question as to what extent depression severity differs depending on the four acculturation strategies.
Methods
Recruitment
The study was conducted at a psychiatric outpatient clinic specialized on Vietnamese migrants at Charité-Universitätsmedizin, Department of Psychiatry and Psychotherapy, Campus Benjamin Franklin in Berlin, Germany.
All patient-related data were collected between 2013 and 2016. All participants were patients of Vietnamese origin, first-generation migrants, seeking culture-sensitive counseling and psychiatric or psychotherapeutic treatment in their native language. The ethical committee granted ethical approval for the conduction of this study at the Charité-Universitätsmedizin, Berlin. All patients gave written informed consent that collected data would be anonymized and used for research and publication purposes only. Before first consultation and treatment, all patients were asked to fill out a structured survey in the Vietnamese language via self-reported paper-pencil assessment. This structured survey included questionnaires assessing socio-demographic information, migration-related factors, acculturation and a clinical psychiatric evaluation (Ta et al., 2015).
Study participants had to meet the following inclusion criteria: first-generation migration status, that is, people born and socialized in Vietnam, who utilized the outpatient clinic and presented with a current depressive episode (International Statistical Classification of Diseases and Related Health Problems 10 (ICD-10) F32.x, F33.x) according to ICD-10 (Dilling, Mombour, & Schmidt, 2005). Additionally, all included patients did not meet the ICD-10 criteria for other comorbid psychiatric disorders.
Measures
Translation procedure
All questionnaires used in the study were translated into Vietnamese using a 4-step back-translation approach (Beaton, Bombardier, Guillemin, & Ferraz, 2014).
Acculturation measure
Acculturation was measured with the Stephenson Multigroup Acculturation Scale (SMAS) consisting of a 15-item DSI subscale and a 17-item ESI subscale (Stephenson, 2000). The DSI subscale measures participants’ identification toward their mainstream society; an example item is ‘I know how to prepare Anglo American food’. The SMAS was adapted by replacing terms in the DSI subscale referring to Anglo-American with German. The ESI subscale measures participants’ identification toward their heritage society; an example item of this subscale is ‘I know how to read and write my native language’. Both subscales have a reportedly high internal consistency with Cronbach’s alpha of .97 and .90.
Participants were asked to score each item on a 4-point Likert scale (1 = false, 2 = partly false, 3 = partly true, and 4 = true). The first item of the DSI subscale ‘I understand German, but I am not fluent in German’ was excluded because it comprises two statements, which confused participants while filling out the questionnaire. The fourth item of the ESI subscale ‘I have never learned to speak the language of my native country’ was excluded, because the study sample consists exclusively of first-generation Vietnamese migrants, thus assessing this item was obsolete. Both, the DSI (α = .81) subscale and the ESI (α = .80) subscale, showed an acceptable internal consistency in our study. Summative scores for each subscale with higher scores indicating a greater level of immersion toward the dominant, German or the ethnic, Vietnamese society were calculated.
Assessment of depressive symptoms
Depressive symptoms were assessed with the 21-item version of the Beck Depression Inventory-II (BDI-II; Beck, Steer, & Brown, 1996). Each item was rated on a 4-point scale ranging from zero to three, assessing the severity level of the symptoms over the past 2 weeks. The study sample demonstrated overall high internal consistency (Cronbach’s α = .93).
Statistical analysis
Statistical analyses were calculated with IBM SPSS Statistics for Mac OS X, Version 22. Demographic group differences regarding continuous variables were analyzed with analyses of variance (ANOVAs) and differences regarding ordinal variables were tested with chi-square tests (χ2). If cell size was < 5, Fisher’s exact test was used instead of χ2-test because of its sensitivity to sample size. Hypotheses were tested using Pearson’s product-moment correlation coefficients, hierarchical regressions, ANOVA and a priori planned contrasts. Effect sizes of the group differences are reported by eta-squared (η2), whereby values up to .01 are classified as small, .09 as moderate and .25 as large effects (Cohen, 1988).
Results
Participant characteristics
A total of 145 Vietnamese patients matched the inclusion criteria. However, cases missing more than 10% of data points were not included in the analysis. Accordingly, full data sets were available for 113 patients, who were diagnosed with an F32/3.x diagnosis (current depressive episode) according to ICD-10 criteria. The mean age of the final sample was 44.74 years (SD = 11.83, range = 16–63) with 73% female and 27% male patients. On average, patients have lived in Germany for 14.6 years (SD = 10.9, range = 0–37). Regarding migration pathways, 10% (n = 11) of the patients came to the FRG as ‘Boat people’, 24% (n = 27) of the patients came to the GDR as guest workers, whereas the remaining 66% (n = 75) belong to the third migration flow. Mean age of migration from Vietnam was 28.4 years (SD = 9.99, range = 11–58). There were no significant differences between age, F(3, 112) = 1.85, p > .05, and years of education, F(3, 112) = 2.26, p > .05, among the four groups of acculturation strategies. There was also no significant difference regarding sex (p = .64). However, there were significant differences in years lived in Germany, F(3, 112) = 7.8, p < .001.
Classification into acculturation strategies
To identify acculturation strategies for each patient, each median of the two acculturation scales was used to dichotomize the scales (median split), that is, DSI (Mdn = 32, range = 18–47) and ESI (Mdn = 57, range = 28–64). This approach resulted in 37 patients (33%) as classified with an integration strategy, DSI and ESI > Mdn, 20 patients (18%) with an assimilation strategy, DSI > Mdn and ESI ≤ Mdn, 24 patients (21%) with a separation strategy, DSI ≤ Mdn and ESI > Mdn, and 32 patients (28%) with a marginalization strategy, DSI ≤ Mdn and ESI ≤ Mdn. Table 1 summarizes the demographic data for each of the four acculturation strategies.
Descriptive statistics of demographic variables of the sample (N = 113) for each acculturation strategy.
SD: standard deviation.
Association between acculturation and severity of depression
The first part of the analyses tested the hypothesis that both, higher DSI and ESI are associated with lower severity levels of depressive symptoms. Preliminary analyses were performed to ensure that there was no violation of the assumption of normality, linearity, multicollinearity, and homoscedasticity. Pearson’s product-moment correlation coefficients were calculated (see Table 2). Hierarchical multiple regressions were used to determine whether the addition of DSI and ESI improved prediction of the level of depression beyond the controlling variables age, sex, education and migration pathway.
Descriptive statistics and correlations for sex, age, education, migration pathway, DSI, ESI and depressive symptoms (BDI-II).
DSI: dominant society immersion; ESI: ethnic society; BDI-II: Beck Depression Inventory-II. N = 113. *p < .05; **p < .01, two-tailed.
The first analysis was conducted with the BDI-II as a dependent variable. Table 3 displays the unstandardized regression coefficients (B), the standardized regression coefficients (β), adjusted R2 and R2-Change after entry of all five predictors. Age, sex, education and migration pathway (guest worker vs boat people vs third wave migrants) were entered into step 1 and only explained for 3% of the variance in the level of depression. After entering DSI and ESI in the second step, the model yielded an adjusted R2 = .06, F(6,104) = 2.12, p = .059, indicating that about 6% of the variance in the level of depression is predicted by DSI and ESI. Both DSI (β = −.20, p = .044) and ESI (β = −.22, p = .03) were statistically significant. The results are consistent with the hypothesis and suggest that DSI and ESI is predictive of depressive symptoms, and specifically that more orientation toward the dominant, German and the ethnic, Vietnamese society was associated with lower levels of depressive symptoms at the initial consultation.
Hierarchical regression of sex, age, education, migration pathway, DSI, and ESI on depressive symptoms (BDI-II).
DSI: dominant society immersion; ESI: ethnic society; BDI-II: Beck Depression Inventory-II. N = 113. *p < .05; **p < .01, two-tailed.
Severity of depression across acculturation strategies
To test the hypothesis of whether the level of depression, in Vietnamese patients, differs depending on the four acculturation strategies, a one-way between-subjects ANOVA was conducted. There was a significant overall main effect of acculturation strategy on reported severity of depression, F(3, 109) = 5.44, p < .01, η2 = .13. A priori planned contrasts were formulated and tested to examine the hypothesis if integrated patients reported less severity of depression than marginalized patients. Consistent with the hypothesis, the severity of depressive symptoms of integrated patients was significantly lower compared to marginalized patients, t(109) = 3.89, p < .001 (see Figure 1).

Differences in severity of depression (BDI-II) between the four acculturation strategies. Error bars represent the standard errors of the mean; *** p < .001, two-tailed.
Discussion
The first part of the study demonstrated that the two dimensions of acculturation, namely orientation toward the German society and the Vietnamese society were associated with less severe depressive symptoms among a sample of Vietnamese psychiatric outpatients. These findings are consistent with several studies among Asian US-Americans, which also found a negative relationship between an orientation toward the mainstream society and depression (Gupta et al., 2013).
In the second part of the study, we investigated whether the severity of depression differed depending on the acculturation strategy, postulated by Berry (1997, 2005). Our findings indicate that integrated patients were associated with less severe depressive symptoms, whereas marginalized patients were associated with the highest severity level of depression. The results align with prior studies as well as Berry’s conceptualization, which proposes a beneficial effect when migrants adopt an acculturation strategy aimed at living a successful life in any cultural context of both mainstream society and heritage society (Berry, 2005; Nguyen & Benet-Martinez, 2012). Furthermore, these positive findings of adopting an integrated acculturation style are consistent with a study conducted by Behrens, Del Pozo, Großhennig, Sieberer, and Graef-Calliess (2014) in Germany. Their study demonstrated that integration was associated with the lowest depression severity among a sample of migrant outpatients. In contrast to our results, this study revealed that assimilated patients showed the highest severity of depressive symptoms. According to Behrens et al. (2014), assimilation involves the denial of one’s cultural roots and socialization, which might be associated with identity crises and thus increase vulnerability to depression.
However, in line with our results, other authors argue that the absence or loss of feelings of belonging may be even more harmful than either denying one’s heritage culture (i.e. assimilation) or not participating in the mainstream culture (i.e. separation). Recent anthropological research indicates an association of the absence of cultural orientation with a lack of the sense of belonging. Pfaff-Czarnecka (2013) defines belonging ‘… as an emotionally charged, ever dynamic social location – that is a position in the social structure experienced through identification, embeddedness, connectedness, and attachments’. The need to belong is a fundamental human motivation (Baumeister & Leary, 1995), while the lack of this human need has reportedly been associated with deteriorating health outcomes (Keyes & Kane, 2004).
Limitations
There are some limitations to this study and findings should be interpreted in the light of these. Analyses revealed a dropout rate of 22%, which can be attributed to the naturalistic clinical sample consisting of Vietnamese outpatients who visited the outpatient clinic for the first time and possibly have stigmatizing attitudes toward psychiatric treatment (Ta et al., 2016). Initial data acquisition was conducted before receiving psychiatric treatment, thus probably lacking sufficient establishment of trust between therapist and patient. Also, some patients showed rather severe depressive symptoms and therefore might not have been able to fill out all questionnaires during the available time. Although our analysis demonstrated that orientation toward the mainstream society and heritage society are significantly predictive of severity of depression, the explained variance is small. Nonetheless, within the complex context of migration and resettlement, numerous factors besides acculturation impact on mental health outcomes. Nevertheless, this study contributes to the existing literature by showing for the first time that the association can also be found in a clinical sample of Vietnamese migrants.
Furthermore, analyses were based on cross-sectional data, and thus causal implications cannot be drawn. However, some critical interpretations of the found association have to be considered. For instance, patients who are affected by a more severe depressive episode might perceive themselves as less oriented and less participative toward any society. Moreover, most acculturation scales, including the SMAS, focus on assessing behavioral domains (e.g. cooking, praying, and other participating activities) of acculturation. However, such behaviors might often be reduced as part of the withdrawal from social situations and activities as a core symptom of depression. This interaction may result in difficulties to disentangle either the influence of the depression or the underlying acculturative strategy. Our results provide a direction for future studies, which can address this open question by including qualitative and mixed-method designs (as discussed below) to capture more facets of acculturation.
Implications for research and clinical practitioners
The present study has several implications to keep in mind for future research and the work of clinical practitioners. Future longitudinal studies are necessary to analyze whether and how acculturation strategies among migrants change over the life-course depending on the particular context and the current developmental task. Drawing on Erikson’s theory of psychosocial development, one developmental task during adulthood comprises ‘generativity’: the passing on of values to the next generation (Erikson & Erikson, 1998; Slater, 2003). Therefore, we hypothesize that assimilation might be highly adaptive within early stages of migration, during which it is important to adapt oneself to the new mainstream society and acquire new skills (Sluzki, 1979). However, toward adulthood, we hypothesize, integration or separation may be more adaptive because migrants might reorient themselves and wish to pass on values and cultural customs of their society of origin to the next generation (Chirkov, 2009; Ozer, 2015).
Additionally, acculturation strategies may be more flexible than earlier conceptualizations acknowledge and even shift over short periods of time, for example, within one day, depending on the social or affective context individuals are part of and are surrounded with (Birman, Simon, Chan, & Tran, 2014; Ward & Geeraert, 2016). A qualitative study among Vietnamese refugees in Norway showed that even extended family members in Vietnam influence the process of acculturation of their kin in Norway (Tingvold, Middelthon, Allen, & Hauff, 2012). We agree that future research on acculturation and mental health outcomes among migrants needs to expand its methodology and theoretical background (Guarnaccia, Hausmann-Stabile, 2016). Future mixed-methods research should include ethnographic interviews to gain an in-depth understanding of the facets of acculturation (Tardif-Williams & Fisher, 2009). Based on those results, researchers may develop more suitable and more flexible acculturation measures rather than maintain a static bi-cultural model.
More generally, our findings also contribute significant implications for clinical work. Knowledge about the different acculturation modes of patients can be useful in the process of developing more effective treatments for various groups such as Vietnamese migrants in Germany. Some scholars have suggested the use of mindfulness-based psychotherapies such as Mindfulness-Based Cognitive Therapy (MBCT; Segal, Teasdale, & Williams, 2002) or Acceptance and Commitment Therapy (ACT; Hayes, Strosahl, & Wilson, 1999) for Asian patients. These third-wave therapies are in part adapted from East Asian philosophies, for instance, Zen-Buddhism and are expected to offer culturally appropriate mental health care (Cook & Hayes, 2010; Hinton, Ojserkis, Jalal, Peou, & Hofmann, 2013; Leong & Kalibatseva, 2011). However, there are important differences between Western-based mindfulness and acceptance-based psychotherapies and Asian cultural values concerning concepts of self, values and communication (Hall, Hong, Zane, & Meyer, 2011). Thus, Hall et al. (2011) proposed a culturally syntonic approach that flexible accentuates culturally relevant components in psychotherapy, for instance, considering the patient’s role within the collective rather than an individualistic approach or defining personal values, which also harmonize with a group and family goals. According to the authors, the effectiveness of culturally enhanced psychotherapies for Asian migrants is moderated by acculturation. The authors hypothesized that Asian migrants who are more oriented toward their heritage society benefit more from culturally enhanced approaches as opposed to those more oriented toward the mainstream society. Therefore, results from this study serve as a helpful heuristic tool to culturally adapt context-sensitive psychotherapies depending on the patient’s level of acculturation.
Furthermore, the results implicate that severely depressed patients with a marginalized acculturation strategy might need additional help. In Germany, people who are disabled have the right to rehabilitation with the aim to be integrated into society (Social Code IX, n.d.). For instance, people with mental illness are entitled to social integration assistance, including measures to promote independent living in sheltered accommodation and assistance with taking part in social and cultural life. Therefore, clinicians should pay close attention and initiate social integration assistance for eligible patients. Furthermore, the identification of the acculturation styles of patients may be applied to improve psychosocial care for migrants in general. As results suggest a link between marginalized patients and higher levels of depressive symptoms, such knowledge may facilitate identification of people with a migration background in general who might be at increased risk for developing mental health disorders (Lynam & Cowley, 2007).
In conclusion, what stands out in this present study is, that even in a clinical sample, integrating both the orientation toward the mainstream society and one’s heritage society might serve as a potential resource, while the rejection of any orientation to any society is associated with an increased risk for depression.
Footnotes
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was conducted in part within the subproject A02 of the CRC 1171 ‘Affective Societies – Dynamics of Social Co-existence in Mobile Worlds’ granted by the German Research Foundation (DFG). This study is part of the dissertation project of Ms. MH Nguyen, M.Sc. We thank all participants who agreed to take part in the study and our research assistant Nadia Jula Schwedler and Thi Phuong Anh Dang for her help.
