The purpose of this study was to investigate possible differences in response to CIT in a prospective 8-week open label trial in African-American and Caucasian participants with MDE. Our results indicated that, despite a number of baseline differences in demographics and severity of depression, treatment outcomes were similar. The hypothesis that African-American patients would respond more quickly was not supported. This hypothesis was based upon putative differences in polymorphisms for the serotonin transporter and CYP2C19 genes. A future report will address outcome in relation to these findings.
African-American participants reported fewer years of education and were more likely to be unemployed. They also had a somewhat more severe depression, as reflected in their modestly higher baseline HDRS score, experiencing more suicidal ideation and melancholia, and they were depressed for a longer time than the Caucasians during this current episode. Despite these baseline differences, however, there were no group differences in treatment outcome.
These findings are consistent with recent reports from pharmaceutical industry-sponsored clinical trials [6,21,22]
and by more representative effectiveness trials in psychiatric and primary care settings [18,19,20,34]
. Taken together, they indicate that when careful attention is paid to symptoms and side effects, and doses modified accordingly, ethnic disparities in treatment outcomes can be attenuated. These findings are of significant importance, as they add to the growing perception that access to and quality of care (e.g. availability of services, number and frequency of visits, access to medication, careful monitoring of symptoms with subsequent dose escalations, etc.) rather than individual differences in response, are likely contributors to disparities in outcome [3,9,20]
. As Miranda et al. 
recently stated, “…quality improvement interventions have been shown to decrease disparities in depression care for some minority groups initially experiencing lower quality of care.” (p. 1106). Whether in a clinical trial or in a depression care program, outcomes in minority groups are similar to those for Caucasians, despite differences in SES.
The strengths of this study are the large number of participants from both groups; the characterization of ethnicity; the use of a measurement based care approach to dosage changes; the use of a structured interview to assess the primary outcome variable at each visit; the respectable retention rate; and the frequent meetings, training, and collaboration among the three sites. Finally, and importantly, this was not a secondary analysis of a data set, but a study prospectively designed to look at this question.
A number of limitations of the study are worth noting, including the open label design and lack of a placebo control group. As noted above, our intent was not to conduct another efficacy study of a commonly used antidepressant, but rather to determine whether differences in treatment response would be observed between African-American and Caucasian groups; hence the choice not to include a placebo. Additionally, eight weeks was chosen as the trial length, with no follow-up period, so no claims can be made for the persistence of response. Only non-psychotic and non-hospitalized patients were enrolled, so these findings may not be generalizable to more severely ill patients. Our remission and response rates were higher than those seen in the STAR*D trial 
where there were fewer exclusion criteria; this further limits generalizability. Wisniewski et al. 
recently discussed this issue, drawing attention to the need to increase recruitment of representative treatment seeking participants in clinical trials. Although our study included participants from a wide range of SES, including treatment seeking patients at public clinics, the exclusion criteria did not allow for a true representation of those seeking treatment (e.g. concurrent substance abuse and significant comorbid illness). Also, other ethnic minority groups were not studied, so caution needs to be exercised in generalizing these findings to other ethnic groups.
Studies of ethnic group comparisons face many challenges, including the criteria for assigning participants to the categorical dimensions of “race” or “ethnicity”, especially in the absence of an acceptable “gold standard”. However, in order to maximize the face validity of our group assignment, we required participants to report that both parents and four grandparents were self-identified as being from the same ethnic/racial group. We recognized that even within our groups, there was significant SES and biological heterogeneity. Finally, this study did not evaluate the combined effects of medication and psychotherapy for depression.
Despite these limitations, however, this study does address an unmet need: conducting prospective comparative studies in patients who represent diverse ethnicity/racial groups. As the Surgeon General’s report indicated 
, this is an area where further study must be undertaken if we are to provide appropriate care to the increasingly diverse population of the United States. This study adds to the growing body of evidence that a key factor in the pattern of ethnic differences in mental health care might relate more to differential access to quality mental health care than to individual response to treatment. In order to test this hypothesis more widely, it will be important to replicate these findings in trials with other underserved and understudied ethnic groups.