Journal of Affective Disorders 104 (2007) 175 – 178 www.elsevier.com/locate/jad Brief report Lower rates of depression in westernised Chinese in the US☆ Gordon Parker ⁎, Bibiana Chan, Dusan Hadzi-Pavlovic School of Psychiatry, University of New South Wales, Australia Black Dog Institute, Sydney, Australia Received 9 February 2007; received in revised form 22 February 2007; accepted 23 February 2007 Available online 30 March 2007 Abstract Background: Low reported rates of depression in Chinese populations could reflect real or artefactual factors, and might be clarified by studying acculturated Chinese in western regions. We therefore sought to determine whether reported rates of depressive disorders differ in resident Chinese and matched nonChinese controls in a large US community survey. Method: We accessed data from the US National Epidemiological Survey of Alcoholism and Related Conditions, involving 306 Chinese subjects and 306 matched non-Chinese subjects. Results: The Chinese reported significantly lower lifetime and 12-month major depression rates, and a lower lifetime rate of dysthymia. Similar rates were quantified for Chinese born in the US and Chinese born overseas. The Chinese did not differ from controls in terms of recurrence rates of major depression. Limitation: Due to our matching analytic strategy, the reported statistics (e.g. prevalences) apply to our matched samples and should not be taken as estimates for the population. Conclusions: Findings indicate that westernisation does not eliminate differences in depression rates long described in Chinese regions, and favour a model whereby the Chinese have a lower vulnerability to depression onset. © 2007 Elsevier B.V. All rights reserved. Keywords: Depression; Dysthymia; Epidemiology 1. Introduction ☆ Role of funding source: Funding for this study was provided by the NHMRC (Program Grant 223708) and the Centre for Mental Health. The NHMRC and the Centre for Mental Health had no further role in study design, in the collection, analysis and interpretation of data, in the writing of the report, and in the decision to submit the paper for publication. Contributors: Author Parker designed the study and wrote the protocol. Author Chan managed the literature searches. Authors Chan and Hadzi-Pavlovic undertook the statistical analysis, and author Parker wrote the first draft of the manuscript. All authors contributed to and have approved the final manuscript. ⁎ Corresponding author. Black Dog Institute, Hospital Road, Prince of Wales Hospital, High Street, Randwick NSW 2031, Australia. Tel.: +61 2 9382 4372; fax: +61 2 9382 4343. E-mail address: g.parker@unsw.edu.au (G. Parker). 0165-0327/$ - see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.jad.2007.02.020 We previously reviewed (Parker et al., 2001) literature identifying Chinese individuals as having low reporting rates of depression. While low rates in metropolitan China continue to be reported (Shen et al., 2006), higher rates have been reported in other Chinese regions. For example, in Taiwan – where depression rates were also once quantified as significantly low, quite high rates have been reported in recent years – both in older subjects (Chong et al., 2001) and in adolescents (Gau et al., 2005). Chen (2001) has suggested that differences in case-finding methods may largely account for such differences in rates. Thus, differences may reflect artefactual (e.g. denial, 176 G. Parker et al. / Journal of Affective Disorders 104 (2007) 175–178 methodological) or cultural factors (e.g. stoicism, acceptance of destiny, family support). As cultural impact is difficult to examine directly, acculturation studies in western regions can be informative. In a study of Chinese Americans living in Los Angeles (Takeuchi et al., 1998), lifetime and 12-month rates of major depression were 6.9% and 3.4% respectively, distinctly lower than U.S. National Comorbidity Study rates (Kessler et al., 1994). In an Australian study (Parker et al., 2005) of Chinese and non-Chinese control subjects, acculturation impacted on reporting of episodes, lifetime depression and help-seeking rates. Any test of the acculturation hypothesis would benefit from a rigorous epidemiological community-based controlled study, with a recent US community study providing such an opportunity. 2. Methods 2.1. Dataset The US National Institute on Alcohol Abuse and Alcoholism (NIAAA) undertook the National Epidemiologic Survey of Alcoholism and Related Conditions (NESARC) across 2001–02. The NESARC dataset (NIAAA, 2005) is publicly available (http://niaaa.census.gov). We accessed the dataset and associated files on 10-November-2005. 2.2. Sample Face-to-face diagnostic interviews generating DSMIV diagnoses were administered by lay interviewers to 43,093 respondents (81% response rate), with Hasin et al. (2005) observing that the NESARC was able to estimate the prevalence of major depression disorder in minority groups as a result of the large sample size. For our analyses, we selected all 306 subjects who reported their ‘origin of descent’ as Chinese, and matched them (by age, sex, marital status, highest education completed, employment status and total family income) to non-Black, nonHispanic control subjects. If multiple control matches were available, one subject from the pool was randomly selected using the SPSS 13.0 statistical program (SPSS 13.0 for Windows, 2004). 2.3. Matching Chinese subjects and matched controls did not differ on any socio-demographic variable. Specifically, the mean age of both was 42.3 years (SD16.5) and 47.1% in each group were male. Educationally, 10.8% and 10.1% respectively had not reached high school, 14.7% and 15.4% completed high school or equivalent, and 74.5% and 74.5% had been educated beyond high school (χ2 = 0.11, df 2, p = 0.95). Full-time employment rates were 57.2% and 59.2% respectively (χ2 = 0.24, df 1, p = 0.62). In relation to marital status, 26.1% and 25.8% had never married, 59.2% and 61.1% were married or in a de facto relationship, and 14.7% and 13.1% were divorced, separated or widowed (χ 2 = 0.40, df 2, p = 0.32). Total family income distribution (across four bands ranging from less than $25,000 to $80,000 or more) was similar (χ2 = 2.7, df 3, p = 0.44). 2.4. Depression measures We report prevalence data for DSM-IV-defined major depression and dysthymia. In relation to help-seeking strategies (assessed as helping “improve your mood or make you feel better”), we selected subjects who met criteria for ‘Lifetime Major Depression’ and examined rates of affirming four separate ‘Yes/No’ questions: (1) Did you ever consult any kind of counselor/therapist/ doctor/psychologist?; (2) Were you a patient in a hospital for at least one night?; (3) Did you ever go to an emergency room?, and (4) Did a doctor ever prescribe any medicines or drugs to improve your mood? 2.5. Statistical analyses For the matched Chinese and controls subjects, McNemar tests were used to compare diagnostic rates. However, as there were few matched pairs of those meeting lifetime major depression criteria, Chi-square tests were used to compare help-seeking rates in all subjects and controls meeting such criteria, while several dimensional variables (e.g. age of onset, number of episodes and age of the most recent episode) were analysed by t-tests. Data on duration of most recent and of longest episode were compared using Mann– Whitney U tests due to large differences in variances between the two groups on those variables. 3. Results 3.1. Prevalence rates The Chinese were significantly less likely to report lifetime episodes of major depression as indicated by McNemar test (6.5% vs 20.3%, p b 0.001; OR = 0.28, 95% C.I. 0.16–0.48), or an episode in the preceding 12 months (3.3% vs 9.2%, p b 0.01; OR = 0.36, 95% C.I. 0.17–0.74) — before and after excluding those judged as 177 G. Parker et al. / Journal of Affective Disorders 104 (2007) 175–178 having substance or illness-induced episode, and significantly less likely to have met criteria for dysthymia (see Table 1). Rates of lifetime depression were comparable for Chinese born in the US and Chinese born overseas (i.e. 6.7% vs 6.5%, df 1, χ2 = 0.003), as were rates for those either born in the US or migrating to the US before the age of 11 years as compared to the remaining Chinese (i.e. 7.3% vs 6.4%, df 1, χ2 = 0.076). analysed data for several anxiety disorders. McNemar tests indicated significantly lower (p b 0.05) rates of Panic Disorder (OR = 0.31, 95% C.I. 0.10–0.50) and Specific Phobia (OR = 0.41, 95% C.I. 0.20–0.82) in the Chinese. Similar trends for Generalized Anxiety Disorder (OR = 0.40, 95% C.I. 0.16–1.03) and Social Phobia (OR 0.67, 95% C.I. 0.30–1.47) were not formally significant. 3.4. Depression help-seeking variables 3.2. Other depression variables For those reporting a lifetime episode of major depression, Chinese and control subjects did not differ by age of onset (27.6 vs 29.8, df 79, t = 0.54), age at most recent episode (34.3 vs 34.9, df 76, t = 0.87), mean number of episodes (7.5 vs 5.5, df 72, t = 0.45), or duration of most recent episode (U = 417.0, df 78, p = 0.08) but the Chinese reported a briefer duration for the longest episode (U = 376.0, df 77, p = 0.05). 3.3. Anxiety disorders As the lower depression rates in the Chinese might have reflected stigma associated with depression, we For mood states, rates of attending any professional were lower in the Chinese (30.0% vs 59.7%, df 1, χ2 = 5.3, p b 0.025), as was receipt of medication (20.0% vs 56.5%, df 1, χ2 = 8.1, p = 0.005). Hospitalization rates (10.0% vs 11.3%, df 1, χ2 = 0.03) and attendance rates at an emergency room (15.0% vs 9.7%, df 1, χ2 = 0.44) did not differ. 4. Discussion The NESARC sample is the result of a complex sampling procedure, generally requiring stratification and associated weighting in analyses. Because of our matching analytic strategy, these weights have not been used, so Table 1 Rates of DSM-IV-defined depressive states in Chinese subjects and controls Diagnosis Major depression — lifetime Chinese Yes No Major depression — last 12 months Chinese Yes No Major depression — prior to last 12 months Chinese Yes No Major depression — last 12 months (substance and illness-induced cases excluded Chinese Yes No Major depression — prior to last 12 months (substance and illness-induced cases excluded) Chinese Yes No Dysthymia — lifetime Chinese a Binominal distribution used due to small cell size. Yes No Controls Yes No 4 16 58 228 Controls Yes No 0 10 28 268 Controls Yes No 2 15 54 235 Controls Yes No 0 9 24 273 Control Yes No 2 14 50 240 Control Yes No 0 2 21 283 McNemar test, χ2 df = 1 p Odds ratio 95% C.I. 22.7 p b 0.001 0.28 0.16–0.48 7.6 p b 0.01 0.36 0.17–0.74 20.9 p b 0.001 0.28 0.15–0.49 5.9 p b 0.05 0.38 0.17–0.81 19.1 p b 0.001 0.28 0.16–0.51 a p b 0.001 0.10 0.02–0.40 178 G. Parker et al. / Journal of Affective Disorders 104 (2007) 175–178 that reported statistics (e.g. prevalences) apply to the matched samples and should not be taken necessarily as prevalence estimates for the wider population. We have previously considered (Parker et al., 2005) the impact of culture on depression rates by comparing Chinese and non-Chinese subjects in an Australian sample, and using several direct and indirect measures of acculturation. The current study uses two relatively ‘blunt’ indirect measures of acculturation (i.e. born in the US, and years in the US), clearly a simplification when acculturation is a multi-faceted and complex process. If, as is commonly described (see Parker et al., 2001) the family provides the primary socialisation and valueengendering arena for the Chinese, the US sample members may have resisted many of the general acculturative westernising influences of the broader geographical region. Further, as many of the Chinese subjects may have continued to use the Chinese language as their primary language, this may have shaped their interpretation and communication on emotional issues, with such linguistically-mediated nuances possibly contributing to sample differences. It does seem reasonable to assume, however, that Chinese born and raised in a western region have experienced at least some level of acculturation — and that the persisting cultural influences intrinsic to being Chinese then contribute to the distinctions identified in this study. Our analyses indicated lower reported rates of depression in a Chinese group resident in a western region. Neither being born in the US nor duration of residence influenced rates. However, the trend for the Chinese to be less likely to meet DSM-IV diagnostic criteria did not appear loculated to depression, and so trended across four anxiety disorders. Such findings allow multiple explanations, including a general response bias (e.g. denial), differential resistance to psychological illness (e.g. stoicism) or differential coping (e.g. minimising psychological distress). In light of their long residency in the US, it is unlikely that case-finding nuances contributed to the differential. Additional analyses – quantifying the extent to which the Chinese were less likely to seek professional help or take antidepressant medication – therefore point to greater resilience in the Chinese. While the Chinese had lower lifetime major depression rates, those experiencing an episode did not differ from controls on age at first or current episode, number or duration of episodes. It may be that the Chinese differ in their threshold to depressive illness onset, but once depression is expressed, it adheres to the familiar western trajectory. Such a model, with a differential impact on onset but not on recurrence allows some refined explanations. The differential pattern favours either greater true resilience (whether culturally or otherwise mediated) influencing onset or a differential response and reporting style. Our key finding, however, is that westernisation does not appear to eliminate the differential reporting long described in indigenous Chinese regions. Acknowledgments We thank the National Institute on Alcohol Abuse and Alcoholism (NIAAA) for making available the dataset. References Chen, A.T., 2001. Case definition and culture: are people all the same? Br. J. Psychiatry 179, 1–3. Chong, M.-Y., Tsang, H.-Y., Lee, Y.-H., Tang, T.-C., 2001. Community study of depression in old age in Taiwan. Br. J. Psychiatry 178, 29–35. Gau, S.S., Cong, M.Y., Chen, T.H., Cheng, A.T., 2005. A 3-year panel study of mental disorders among adolescents in Taiwan. Am. J. Psychiatry 162, 1344–1350. Hasin, D.S., Goodwin, R.D., Stinson, F.S., Grant, B.F., 2005. Epidemiology of major depressive disorder. Arch. Gen. Psychiatry 62, 1097–1106. Kessler, R.C., McGonagle, K.A., Zhao, S., Nelson, C.B., Hughes, M., Eshleman, S., Wittchen, H.U., Kendler, K.S., 1994. Lifetime and 12-month prevalence of DSM-III-R psychiatric disorders in the United States. Results from the National Comorbidity Survey. Arch. Gen. Psychiatry 51, 8–19. NIAAA: National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) 2005. http://niaaa.census.gov (Accessed 10 November 2005). Parker, G., Gladstone, G., Chee, K.T., 2001. Depression in the planet's largest ethnic group: the Chinese. Am. J. Psychiatry 158, 857–864. Parker, G., Chan, B., Tully, L., et al., 2005. Depression in the Chinese: the impact of acculturation. Psychol. Med. 35, 1475–1483. Shen, Y.-C., Zhang, M.-Y., Huang, Y.-Q., et al., 2006. Twelve-month prevalence, severity, and unmet need for treatment of mental disorders in metropolitan China. Psychol. Med. 36, 257–267. SPSS 13.0 for Windows (2004). Chicago: SPSS Inc. Takeuchi, D.T., Chung, R.C., Lin, K.-M., et al., 1998. Lifetime and twelve-month prevalence rates of major depressive episodes and dysthymia among Chinese Americans in Los Angeles. Am. J. Psychiatry 155, 1407–1414.