Prevalence and Determinants of Psychiatric Disorders Among South Asians in America

Initial research into the mental health of Asian Americans tended to treat them as a single category, without addressing different Asian subethnic groups. This was done largely to increase sample sizes (1). These studies tended to show that fewer Asians met criteria for psychiatric disorders than Caucasians and that fewer Asians sought psychiatric services (2, 3). It has also been found, however, that this practice of treating Asian Americans as a single population in psychiatric research studies obscures significant differences in the level of psychiatric disability between the multiple subethnic groups making up the Asian American whole (1).

The first nationwide American survey of mental health focusing specifically on minorities, including a range of Asian subethnic groups, was the National Latino and Asian American Survey (NLAAS) of 2002–2003 (4). It was largely funded by the National Institute of Mental Health under a mechanism for cooperative grants, along with the National Survey of American Lives, which was a survey of black Americans, and a replication of the National Comorbidity Study. These studies formed a cooperative agreement, the Collaborative Psychiatric Epidemiologic Studies (CPES), allowing the sharing of ideas, protocols, and measures. Following the NLAAS was the NLAAS II, a 3-year CPES initiative using NLAAS data to compare the prevalence of psychiatric disorders among Asian Americans, Latino Americans, and whites to localize disparities in mental health service provisions to these populations and to delineate differences in the patterns of use of mental health services (5).

Through examining NLAAS data, Masood et al. (6) found that compared to previously published NLAAS data on rates of psychiatric disorder among all Asian Americans, a smaller percentage of South Asians met criteria for psychiatric disorder (6). The lifetime prevalence of having ever met criteria for DSM-IV affective, anxiety, or substance abuse disorder was 20.8% in South Asians compared with 26.8% in all Asian Americans. For affective disorder, the prevalence was 2.7% in South Asians compared with 9.1% in all Asian Americans, while for anxiety disorder it was 5.3% in South Asians compared with 9.8% in all Asian Americans (6).

The National Epidemiologic Survey of Alcohol and Related Conditions (NESARC) of 2002, which surveyed Americans for alcohol use disorders and for comorbid mood and anxiety disorders, while not focused specifically on minorities, also provides information on rates of these disorders among South Asians. In the Lee et al. (7) study of NESARC data, the South Asian sample had a 24.5% lifetime rate of any DSM-IV mood, anxiety, or substance use disorder, while this rate was 36.4% among Southeast Asians and 22.5% in East Asians. Prevalence of mood disorder was 13.1% in South Asians, 16.9% in Southeast Asians, and 13.4% in East Asians, while prevalence of anxiety disorder was 11.4% in South Asians, 13.4% in Southeast Asians, and 11.4% in East Asians (7).

Similarly to the study by Masood et al. (6), the study by Lee et al. (7) shows that rates of psychiatric disorder among South Asians are toward the low end for Asian Americans. The Lee et al. study also points to the heterogeneity of different Asian groups, with East and South Asians reporting relatively similar rates of disorder, while Southeast Asians had rates that were significantly higher. Accordingly, we should also assume that there is likely to be heterogeneity within the South Asian sample itself, and there may be areas of commonalities between these Asian groups; for example, certain South Asians may share with certain Southeast or East Asians various factors, including religion, socioeconomic status, origin from rural society, and length of time since personal or familial immigration, not shared with other South Asians and that have effects on mental health.

The study by Masood et al. (6) examined the predictors of psychiatric distress in South Asians, conducting multivariate regression analysis to see which factors had associations with an elevated score on the Kessler Psychological Distress Scale (also see Table 1). They found that these factors fell into three categories: those characteristic of the individual, those characteristic of the family, and those characteristic of the extra-familial environment. Among a variety of factors examined, including demographic characteristics, financial situation, cohesiveness of family, and community position, the strongest predictor was found to be family cultural conflict, which describes conflict within the family over appropriation of traditional South Asian norms and values versus American ones. The only other significant predictor of distress was low social position within the South Asian community (6).

The authors completed additional analysis to assess the predictors of distress by gender (6). They found that among women, the most significant predictor was having low extended family support. Additionally, being born in the United States, as opposed to having immigrated, also predicted distress. For men, there were more varied predictors, with the most important being financial strain, family cultural conflict, lower social position in the South Asian community, and higher position in the American social community (6).

Data from the Canadian Community Health Survey (CHHS), an annual survey of various measures of health across Canada, also provides information on potential determinants of mental health among North American South Asians. Islam et al. (8) analyzed 2011 CHHS data to assess whether predictors of mood disorder differed among Canadian-born and immigrant South Asians and found that there were differences: among the Canadian-born population, unemployment and reduced physical activity predicted increased likelihood of mood disorder, while among immigrant South Asians, being female, experiencing food insecurity, poor physical health, smoking, and immigrating at less than 17 years of age predicted increased odds of mood disorder (also see Table 1). Although the study did not compare the rate of mood disorder between the immigrant and Canadian-born populations, what this study certainly suggests is that time of personal or familial immigration interacts with other factors and is an important determinant in and of itself to the risk of psychiatric illness among South Asians in North America. In working with South Asians, then, psychiatric providers should inquire about these individual and environmental/familial circumstances that we now know can have significant effects on psychologic health.

The study by Masood et al. (6) found that while a lower percentage of South Asians met criteria for psychiatric disorder compared with all Asian Americans, the rates of subthreshold anxiety and affective disorders (i.e., meeting some but not all criteria required for diagnosis) were similar between the two groups. Additionally, they found that for South Asian women, meeting criteria for a DSM-IV diagnosis within the past year did not predict psychologic distress. This suggests that Western screening instruments for psychiatric disorder have less sensitivity in South Asians, which may be due to differences in reporting or because symptoms of psychiatric illness manifest differently in South Asians than in other ethnic groups (9, 10).

Furthermore, South Asians may experience psychiatric symptoms not as indicators of illness but as appropriate reactions to life stress, leading them to seek support of friends rather than consulting with mental health professionals (10). This is consistent with 2003 CCHS data showing that among South Asians who had experienced a recent major depressive episode, only 37.5% had used mental health services, while among whites experiencing recent depression, 46.2% had used services (11). Another factor potentially preventing South Asians from seeking professional treatment is stigma surrounding mental illness (12, 13).

South Asians are more likely to have diabetes and atherosclerosis than are other ethnic groups in America (14, 15). Because many psychopharmacologic treatments cause metabolic side effects, this risk-benefit ratio should be considered carefully. Another biologic characteristic affecting psychiatric treatment is that members of the Vysya community of Southern India possess a higher than normal rate of pseudocholinesterase deficiency, a reduction in succinylcholine metabolism that impairs motor recovery from succinylcholine (16). Accordingly, members of this community who are ECT candidates could be administered an alternate, non-depolarizing muscle relaxant (17).

In order to improve detection, and ultimately to improve delivery of psychiatric services to this population, further research is needed toward the development of culturally sensitive screening tools, and investigating how to optimally deliver psychiatric care to a population in which mental illness is often regarded with shame or fear. Lastly, an area that would benefit from increased attention is rates of psychotic disorder and utilization of psychiatric services among South Asians with psychosis, who are likely to be a highly underserved group.