Background: Differential diagnosis of schizophrenia and bipolar disorder is a challenging but important task. These conditions often exhibit overlapping clinical symptomatology, but have different prognoses and pharmacological management strategies. Factors other than clinical presentation may influence diagnosis. Past studies suggest that ethnicity is one such factor, with variations observed in diagnostic rates of serious mental illness (SMI). With increasing attention paid to provider cultural competency, we investigate current diagnostic practices within a veteran population.
Method: Controlling for patient need characteristics and illness severity, we examine whether ethnic differences in diagnosis continue to exist. If so, race may adversely enter the evaluation process. A national database of all SMI veterans explores the relationship between ethnicity and diagnosis. The role of symptomatology is also examined. Given minimal variation in veteran socioeconomic status, the Department of Veterans Affairs (VA) provides a natural setting to address this confounding factor. The 1999 National Psychosis Registry provides a sample of 134,523 veterans diagnosed with schizophrenia, schizoaffective disorder, or bipolar disorder. Multinomial logistic regression yielded odds ratios (OR) for being diagnosed with schizophrenia versus bipolar disorder; the schizoaffective versus bipolar risk was likewise assessed, exploring theoretical aspects of a psychosis-affective 'continuum'.
Results: Small effects were observed for being male, single or rural resident. However, the demographic characteristic most strongly associated with a schizophrenia diagnosis was race. The OR for African Americans was 4.05, and 3.15 for Hispanics. Similar though less dramatic results were revealed for schizoaffective disorder.
Conclusions: This study confirms continued ethnic disparities in diagnostic patterns, and highlights the importance of recognizing ethnic differences in symptom presentation while emphasizing greater cultural competency.