The Tibetan translation of the PHQ-9 will be important for screening and understanding the prevalence of depression symptoms among Tibetans and Tibetan refugees faced with dynamic globalization and economic and cultural insecurity. We demonstrate that the Tibetan PHQ-9 has acceptable reliability and holds promise as a clinical instrument. Our exploratory factor analysis indicates that the Tibetan PHQ-9 has a single factor structure, as is consistent with many previous studies (22–25) While other studies have supported a two-factor model, corresponding to somatic (e.g. sleep, appetite, and fatigue items) and non-somatic or affective symptoms (e.g. mood, suicidal thought items) (26–29), our data do not support such a model. Although the Tibetan PHQ-9 used here demonstrates acceptable reliability, it appears to have a lower alpha than has been found in other studies, many of which have yielded alpha levels above 0.80 (e.g. (20, 22, 25, 30–32)). The lower reliability may reflect something about the current translation, or it may reflect true differences in the way that symptoms are interpreted, experienced, or reported by this unique study population.
With respect to individual item performance, these data indicate that all items were important to the overall construct. However, there was variance in item endorsement. Consistent with other studies, very few monastics endorsed experiencing suicidal ideation (33). The most commonly endorsed item, on the other hand, was ‘Low energy’, and the majority of the monastics (> 60%) reported experiencing this symptom at least several days per week. Several studies conducted among Asian populations have found higher rates of somatic symptoms (sleep problems, low energy, and appetite change) (for example, (33–36)). While, the monastics in this study only had relatively higher rates of endorsement of ‘Low energy’, they did not have higher rates of other somatic symptoms. Taken with the single-factor model identified with these data, this study is not consistent with the characterization of Asian racial/ethnic groups as more likely to experience somatic symptoms of depression and it highlights the importance of moving beyond simple east-west essentialism (37, 38).
While the PHQ-9 is among the most widely used measures of depression and it has proven important as a diagnostic screening tool in many disparate clinical contexts and among diverse populations, the diagnostic utility of the current translation will require further evaluation. Previous research has indicated that diagnostic cutoff scores of 10 are clinically meaningful and have high levels of sensitivity (88%) and specificity (88%), as individuals with major depression seldom score in that range. Scores of 15 or greater usually signify the presence of major depression. Scores in between that range, from 10–14, are associated with less diagnostic sensitivity (20, 39). We used these criteria to interpret the current data; however, future research should examine the diagnostic validity of the T-PHQ-9.
Responses in the current study indicate that 89.3% of monastics fall in the minimal and mild range for depression. Interestingly over 10% of the monastics fell in the moderate and above range, with 2% categorized as experiencing moderately severe or severe depression. Comparing these data to previous studies of nationally representative samples suggests that the monastics do not report demonstrably lower levels of depressive symptoms. The point prevalence rates for depression in an American sample of adults was recently estimated at 8.1% (40). For men in the sample, the prevalence was 5.5%, compared to 10.4% for women. Another study estimated that 95% of Germans fall into the minimal and mild range, with fewer people falling in the moderate and high range than we found in the current sample (24). Prevalence rates among adults in Sweden are comparable to rates observed in the monastics in this study, with 10.8% reporting clinically significant depression (41). While clinical interpretations of these data warrant great caution, our preliminary findings indicate that the T-PHQ-9 is sensitive to variation in depression symptoms and that it appears to be operating similarly to other population studies that evaluate the point prevalence of depression.
Careful consideration, however, should be given to determining the most appropriate comparison groups to interpret the current data; the monastic science students may have more in common with other student populations than with a more general adult population. Within student populations, there appears to be a relatively large amount of variance in PHQ-9 scores. For example, in a study of Chinese medical students, the mean PHQ-9 score was 6.02 and 13.5% of respondents reporting moderate to severe depression (10–27 range) (42). Similarly, a large study of South Korean medical students found that 13.7% of students scored in the moderate to severe range (43). A study of medical students in Cameroon found that 30.6% scored in the moderate to severe range (44). There also appears to be extensive variation in prevalence of depression among university students, with rates of depression ranging from 10–85% (45). Depression levels in the current study were at the bottom-end of what is generally seen in studies of university and post-graduate students.
If rates of depression among Tibetan Buddhist monastics are similar to or higher than rates found in other populations, some thoughts are warranted as to what factors influence this effect. Several large studies point to factors that exert direct effects on risk of major depression, including income, sleep disorders, and chronic diseases (46). Other studies find associations between nutritional status, adiposity, and physical activity and rates of depression (14, 44, 47). Monastics may experience lifestyle factors that put them more at risk for depression, a possibility that warrants further inquiry. Large bodies of research have found that education (48, 49) and religiosity (50, 51) are protective against depression, which would suggest that monastics may be relatively buffered from experiencing depression. However, another study of Tibetan refugees living in India found lower prevalence of depression and importantly found no association between monastic status or educational variables and depression levels (52). Taken together, it may be that some monastics in our study experience a suite of lifestyle risk factors that have a net negative impact on their well-being.
In addition to common risk factors associated with elevated risk for depression, monastics in our sample may experience specific burdens that impact their experience of depression symptoms. Tibetan culture and traditions, including the growth and development of Monastic universities serve the purpose of maintaining Tibetan culture in the hope of a future repatriation to the ancestral homeland. A community in diaspora navigates the present circumstance with great care. By definition, the aspirations of the community are to return, but the reality requires the laying down of a local foundation. As the years pass, all that may be known is the current reality, and the more settled in place, the weaker the claim becomes for repatriation. Diaspora communities’ risk adverse mental health as a consequence of state impermanence (53).
Limitations and future directions
For several reasons, caution is warranted with diagnostic claims or interpretations of the current data. First, as stated above, we did not conduct any validity estimates within the current study. Future research should examine convergent validity of the T-PHQ-9 and other validated instruments, as well with clinical diagnostic methods. Second, we were not able to conduct any qualitative evaluations to explore how monastics understood and related to the translated items. In future research, we will conduct semi-structured cognitive interviews with a different group of monastics enrolled in ETSI in order to examine the clarity and relevance of each item and to understand their cognitive process in answering each item (54). While we performed back-translation and had input from 5 experienced translators, linguistic and cultural differences will impact the way emotions are perceived and interpreted, as well as how distress and symptoms of distress are communicated (38). Related, the monastics are relatively unfamiliar with survey instruments like the PHQ, which may impact the way they thought about the items or answered the survey. The use of cognitive interviewing to understand the translation and understanding of language related to depression symptoms will yield important insights about cross-cultural variation in mental health symptoms.
Another important next step in this research is to examine how age and sex impact monastic depression symptoms. While we did not find a significant difference between monks and nuns, we may have been underpowered to examine whether well-described sex-differences in depression (40, 55) are also evident among this monastic population. Nuns are newly involved with ETSI, and as their representation grows there will be more nuns available to participate in future iterations of this research program. It will also be critical to examine lifestyle risk factors as well as social and cultural influences on monastics’ experience of depression symptoms. Finally, this study raises critical issues related to the ethical obligations and best practices in conducting cross-cultural research at the intersection of mental health. While, again, we must interpret these data with care, they do highlight the potential importance of diagnostic and clinical resources made available to monastics. Preliminary evidence indicates that the T-PHQ-9 is a reliable instrument for these important future analyses.