Across a wide variety of treatment settings and developmental stages, African American patients receive excess diagnoses of schizophrenia-spectrum disorders, as compared with similar white patients (DelBello et al., 2001; Flaskerud and Hu, 1992; Strakowski et al., 1996). Concurrently, African Americans receive fewer mood disorder diagnoses. Although the reasons for the ethnic differences in clinical assignment of psychiatric diagnoses remain unclear, investigators have proposed several hypotheses. One explanation is that there are actual ethnic differences in rates of psychiatric disorders. However, studies of psychiatric patients reveal that when structured diagnostic instruments are used and strict diagnostic criteria are applied, there are fewer differences in the rates of psychotic and mood disorders between ethnic groups (Cuffe et al., 1995; Mukherjee et al., 1983; Robins et al., 1984).
Factors in Misdiagnosis
Misdiagnoses may be due to several factors including ethnic differences in clinical presentation or clinician biases. For example, cultural differences in expression of psychiatric illnesses may account for ethnic differences in clinically assigned diagnoses (Adebimpe et al., 1982; Fabrega et al., 1988; Neighbors et al., 1989). African American patients may exhibit more psychotic symptoms during affective episodes than whites, possibly leading to under-recognition of affective syndromes (Adebimpe et al., 1982; Lawson et al., 1994; Mukherjee et al., 1983). Indeed, Strakowski et al. (1996) found that African American patients demonstrated higher rates of first-rank symptoms, although this did not entirely account for the ethnic differences in psychiatric diagnoses that they found.
In a later study, Strakowski and colleagues (1997) reported that information variance, defined as differences in the clinical data recorded, was the cause of diagnostic disagreement between clinical and research diagnoses 58% of the time and was related to ethnicity. In this study, criterion variance, or how clinical data are applied, was present in only 42% of cases and was not related to patient ethnicity, suggesting that affective symptoms may be missed in African Americans who, more typically than whites, present with psychotic symptoms. In other words, although there might not be ethnic differences in how diagnostic criteria are applied, if an African American patient presents with mood-disorder symptoms, it is less likely to be recorded in the medical record than if a white patient presented with similar symptoms. Together, these data suggest that first-rank psychiatric symptoms in African American patients might distract clinicians, who then fail to elicit mood symptoms for these patients.
Misdiagnoses may also be due to social and cultural differences between predominantly white clinicians and African American patients. Whaley (1998) reported that mild forms of suspiciousness are more prominent in African Americans than in whites and are associated with depression, suggesting that African Americans' culturally based suspiciousness of a white-dominated mental health care system may be misinterpreted as a psychotic symptom. However, most studies investigating ethnic differences in psychiatric diagnosis have had insufficient African American psychiatrists involved in assigning diagnoses to evaluate this factor.Selection Bias
The ethnic differences in rates of psychiatric diagnoses may also be due to biases in rates of hospitalization, i.e., referral biases. However, few studies have investigated ethnic differences in access to mental health care services and assignment of disposition, for example, hospitalization versus incarceration. Cuffe and colleagues (1995) reported that African American females with psychiatric disorders are undertreated in outpatient settings. Perhaps African Americans have a more severe mood disorder, which presents with psychotic symptoms by the time they are admitted to an inpatient treatment facility, thus making them more likely to be diagnosed with a schizophrenia-spectrum disorder.
Several investigators have reported fewer diagnoses of substance abuse in African American adolescents (DelBello et al., 2001; Kilgus et al., 1995). Although the reason for this remains unclear, as Kilgus and colleagues (1995) suggested, drug use may be linked with delinquent behaviors, which may lead more African American adolescents with substance-use disorders to the juvenile justice system as opposed to mental health treatment. Furthermore, Lewis et al. (1980) observed that violent, mentally ill African American adolescents were more likely than similarly violent and ill white adolescents to be incarcerated rather than hospitalized. This could alter the diagnostic distribution of patients admitted to a hospital. Additionally, African Americans may be less likely to trust a predominantly white mental health care system or may be less likely to view mood or substance-use disorders as "mental health" issues, thereby altering referral patterns for inpatient admission. In contrast, Strakowski and colleagues (1995) found that African American adults were more likely to be hospitalized from a psychiatric emergency department and less likely to have a substance-use disorder diagnosis than whites. Differences in study populations might have contributed to the variability in results among studies.