Estimates of Serious Mental Illness by Race/Ethnic Group from the Collaborative Psychiatric Epidemiology Surveys (CPES)

Background: Serious mental illness (SMI) is believed to afflict up to 6% of the US population and to cause considerable pain, suffering and economic burden. To date, the prevalence of SMI has been estimated from epidemiological surveys of English speakers with limited numbers of ethnic minorities, particularly Asian-Americans. Data from the Collaborative Psychiatric Epidemiological Surveys (CPES) present a new opportunity to refine estimates of SMI that include more race/ethnic minority participants and to reliably estimate how SMI may differ by race/ethnic groups.

Objective: To estimate 12-month prevalence of SMI due to DSM IV anxiety, depressive, and substance disorders by race/ethnic group in the CPES.

Method: The CPES (N=20,013) is composed of three national surveys: the National Comorbidity Survey Replication, the National Survey of American Life (which sampled persons of African and/or Afro-Caribbean descent), and the National Latino and Asian American Study (which conducted interviews in Spanish and several Asian languages in addition to English). Each study conducted a nationally representative face-to-face household survey using the Composite International Diagnostic Interview to measure mental health disorder. We estimated the prevalence of three classes of DSM IV disorders: (1)Anxiety: including Agoraphobia, Generalized Anxiety Disorder, PTSD, Social Phobia and Panic Disorder; (2) Depressive: including Dysthymia and Major Depressive Disorder; and (3) Substance dependence: including Alcohol Dependence and Drug Dependence; and calculated the prevalence of SMI within these disorders, using Kessler's operationalization of SMI, by four race/ethnic groups (Black, White, Hispanic and Asian). Other classes of disorders were not included as they were not consistently assessed across the three studies of the CPES.

Results: Across the three classes of disorders, Asians have lower prevalence rates than the other race/ethnic groups (0.4-6.2%). However, of those Asians who do have mental health disorders, a high proportion have SMI, most notably for depressive disorders (53.5%). On the other hand, while whites in general have the highest prevalence of disorder (1.4-13.2%), those with disorder seem to be disabled less often with lower rates of SMI. Blacks were in between Asians and Whites in regards to prevalence. However, they had the highest rates of SMI for depressive and substance disorders, and are a close second to Hispanics for anxiety disorders.

Conclusion/Implications: These findings are the first national estimates of SMI by race/ethnic groups. Results suggest that prevalence of SMI varies greatly by race/ethnic group which raise two overarching sets of questions. The first seeks to affirm whether we have achieved cross-cultural equivalency in defining disorder, and particularly in this case, in defining severity of disorder. If yes, then the second asks what contextual, social, cultural, and/or biological factors can explain such variations in severity of mental disorders across race-ethnic groups; and how can social work researchers and practitioners contribute to this discussion.