We examined illness outcomes in racial-ethnic groups matched on key socioeconomic factors. Compared with their non-Hispanic white comparison groups, African-American and Hispanic patients with bipolar disorder who received care in STEP-BD experienced similar levels of response in terms of depression (MADRS), mania (YMRS), and proportion of days spent well in the study year. However, African Americans had lower global functioning on the GAF than their white counterparts, a difference that was not seen for Hispanic patients and their comparison group. In addition, a trend toward worse overall clinical status over the study year as measured by the CMF was observed for African Americans compared with their non-Hispanic white counterparts. For depression response as measured by the MADRS, African Americans with psychotic symptoms at baseline had poorer outcomes than non-Hispanic whites with psychotic symptoms at baseline.
It appears that psychotic symptoms in bipolar disorder contribute to poor recovery among African Americans to a greater degree than among non-Hispanic whites or Hispanics. It has often been reported that African Americans have higher rates of schizophrenia diagnoses than mood disorder diagnoses compared with rates reported for non-Hispanic whites (21
). In the non-Hispanic white comparison groups in this sample the proportions with psychotic symptoms at baseline (13%–20%) were more similar to the proportions for the entire STEP-BD sample (17%), whereas the proportions of African Americans and Hispanics with psychotic symptoms differed from the proportions in the overall sample. Psychological, social, and biological hypotheses have been proposed for the higher rates of psychosis among immigrant populations of African origin (25
); some have suggested that they result from inaccurate symptom assessment or racial biases.
Increased attention to current and previous psychotic symptoms that takes into account an individual’s racial-ethnic and socioeconomic background should improve the accuracy of diagnosis and symptom characterization. During STEP-BD clinical assessments, some behaviors of African Americans or their symptom reports may have been misinterpreted as psychopathology instead of being more accurately attributed to sociocultural background. For example, a persecutory delusion might be viewed more accurately as primarily anxiety driven rather than as a psychotic symptom. A clinician may misinterpret depressive symptoms as negative symptoms associated with schizophrenia. What is labeled a “lack of insight” resulting from psychosis might be more accurately seen as a lack of familiarity with illness terminology and with mental health service systems. Some African-American patients’ mistrust of mental health providers may be interpreted as paranoia instead of as culturally consistent and perhaps reasonable (26
A previous study found that African Americans were more likely than whites to endorse schizotypal personality traits on a self-report instrument (28
). To better understand the higher rates of psychotic symptoms in bipolar illness among African Americans, it may be useful to include additional measures to help explain outcomes, such as assessing mistrust of health care professionals and experiences of discrimination. Investigators should consider incorporating scales that more comprehensively assess psychotic symptoms and administering such scales along with measures of other symptoms in bipolar disorder. Semistructured rating scales that systematically assess symptoms across ethnic groups are recommended (29
). A semistructured approach would also allow for clinical judgment in regard to contextual factors; for example, a clinician could ask additional questions to ascertain whether a patient has interpreted a question as intended (30
). The Bipolar Inventory of Symptoms Scale includes structured questions for assessing symptoms, operationally defines levels of severity, and yields a discrete psychosis factor as one of five fundamental domains (31
). Alternatively, scales commonly employed for assessing schizophrenia, such as the Brief Psychiatric Rating Scale and the Positive and Negative Syndrome Scale, would be adequate for assessing psychotic symptoms. For both instruments, there is preliminary data on validity for use with persons with schizophrenia from ethnic minority groups (33
); however, both have the disadvantage of including numerous items that are uncharacteristic of bipolar disorders.
The results did not support our hypothesis that Hispanic patients would have lower recovery rates. Research on mental health treatment outcomes suggests that when evidence-based practices are applied competently and socioeconomic differences are considered, outcomes are generally similar for Hispanics and non-Hispanics (36
). The single published study of medication treatment of bipolar disorder among Latinos, most of whom were non-U.S. Latinos, reported that in some instances Latinos improved at greater rates than whites (11
Participation by a diverse sample at multiple sites across the United States is a strength of this study. In addition, STEP-BD is the only prospective comparison of outcomes of bipolar disorder among patients from three U.S. racial-ethnic groups. By using frequency-matched groups, we were able to compare African Americans and Hispanics with non-Hispanic whites of similar socioeconomic status, an essential step in comparing outcomes across racial-ethnic groups.
This study has numerous limitations. Because of the demographic characteristics of STEP-BD participants, the generalizability of the results to uninsured persons with bipolar disorder across racial-ethnic groups may be limited. Most participants in our sample had private insurance rather than public insurance, whereas persons with serious mental illness in community samples are likely to have public insurance (38
). Although patient groups were matched by insurance status (yes or no), African-American patients were less likely to have private insurance than participants in the comparison group. It is important to note that although we strove to maintain a socioeconomic balance across groups, other differences that may exist between racial-ethnic groups were not addressed in this study. For example, an examination of treatment adherence would provide valuable information because persons from racial-ethnic minority groups often report lower adherence to medication treatment for psychiatric disorders (39
). This study did not examine medication treatment. Medication regimens varied depending on psychiatrists’ clinical decisions for each patient. Future studies are needed to examine patterns of medication and psychosocial care by racial-ethnic group; if differences are found, studies should assess their impact on outcomes. Several factors that contribute to quality of treatment may have differed by site, particularly at sites with socioeconomic differences, and these factors were not measured in this study. Such factors include provider competence, the extent of community resources, and ease of access to the clinic and to medication. Understanding adherence, quality of treatment, and access to care is an important concern in outcomes studies in which race-ethnicity is examined (12
The GAF rating includes symptom assessment, and thus generalizability to other quality-of-life outcomes is limited. Psychotic symptoms were not assessed with a validated rating scale. Smaller samples in some sub-analyses () limited power to detect differences between the groups, and those analyses should be replicated. A similar limitation exists in regard to gender. In this study, about 75% of African-American participants and 65% of Hispanic participants were female. In STEP-BD, 58% of the sample was female, closer to general population estimates. Thus recruitment of persons from racial-ethnic minority groups in STEP-BD was particularly challenging in regard to African-American males. In STEP-BD, current alcohol and drug use co-morbidity averaged 10%–15%, whereas in a national study rates of current alcohol and drug comorbidity were 29% and 17%, respectively (40
). Thus generalizability of the results to the general population is more limited for males and for persons with comorbid substance use disorders. Analyses of comorbidity and symptom profiles by bipolar type—types I and II—could further elucidate predictors of differential outcomes by race-ethnicity. Study dropout rates were higher in both minority groups than in their comparison groups, and the analyses did not include data from those who dropped out. Thus outcomes are most generalizable to patients who remain in a study and a course of treatment. Finally, focused comparisons of African Americans and Hispanics are recommended to further elucidate racial-ethnic similarities and differences.
Results for Hispanics should be interpreted in the context of the degree of acculturation, which was generally high in STEP-BD (41
). Acculturation was not evaluated in the study reported here, although all persons who participated in STEP-BD were required to be fluent in English. Further studies are needed to assess outcomes for Spanish-speaking persons with bipolar disorder in the United States.