How to avoid ethnic bias when diagnosing schizophrenia
Is your practice bias-free? Examining the misdiagnosis of African-Americans yields insights into how to avoid cultural misunderstandings.
In patients with psychotic symptoms, why are African-Americans more likely than whites to be diagnosed with schizophrenia? After more than 30 years of debate, some answers—and remedies for the problem—are becoming clear.
In psychiatry, where interpersonal interactions are key to eliciting diagnostic symptoms and signs, there is an intrinsic risk of misinterpretation when clinician and patient are of different cultural, ethnic, or socioeconomic backgrounds. This article analyzes four factors that contribute to misinterpretation and to ethnic misdiagnosis of schizophrenia. Culturally sensitive strategies are offered to avoid diagnostic bias in clinical practice.
Large epidemiologic studies report similar rates of schizophrenia and bipolar disorder in African-American and white populations.1 Although patients of both races have been wrongly diagnosed with schizophrenia, the pattern is stronger and more persistent in African-Americans.
Diagnostic criteria for schizophrenia: Characteristic symptoms (Criterion A)
Two (or more) of the following, each present for a significant portion of time during a 1-month period (or less if successfully treated):
- Disorganized speech (eg, frequent derailment or incoherence)
- Grossly disorganized or catatonic behavior
- Negative symptoms (ie, affective flattening, alogia, or avolition)
Note: Only one Criterion A symptom is required if delusions are bizarre or hallucinations consist of a voice keeping up a running commentary on the person’s behavior or thoughts, or two or more voices conversing with each other.
295.30 Paranoid type
A type of schizophrenia in which the following criteria are met:
- Preoccupation with one or more delusions or frequent auditory hallucinations
- None of the following is prominent: disorganized speech, disorganized or catatonic behavior, or flat or inappropriate affect.
In the 1970s, Simon et al2 studied 192 hospitalized patients, of whom all African-Americans and 85% of whites had been identified clinically as having schizophrenia. Using a structured interview, the researchers found that only 40% of the African Americans and 50% of the whites met diagnostic criteria for schizophrenia. African-Americans with mood disorders were found to be at particular risk of schizophrenia misdiagnosis.
In the 1980s, among 76 patients with a clinical diagnosis of schizophrenia, Mukherjee et al3 diagnosed one-half (52%) with bipolar disorder using a structured clinical interview. Schizophrenia misdiagnoses were more common in African-Americans (86%) and Hispanics (83%) than in whites (51%). In particular, African-Americans were most likely to be misdiagnosed with paranoid schizophrenia. African-Americans complained more commonly than whites of auditory hallucinations, which may represent an ethnic difference in symptomatic presentation of psychotic mood disorders.
In the 1990s, colleagues and I conducted two studies—one of 173 patients in a Tennessee psychiatric hospital4 and the other of 490 patients in an Ohio psychiatric emergency service5—and found yet again that African-Americans were more likely than whites to be diagnosed with schizophrenia. In the hospital study, higher rates of schizophrenia diagnosis were associated with lower rates of mood disorder diagnosis. This inverse relationship implied that African-Americans with mood disorders were being misdiagnosed with schizophrenia.
Men were more likely than women to be diagnosed with schizophrenia, suggesting that African-American men were most likely to be misdiagnosed. When adjustments were made for gender, black women were found to be at higher risk for misdiagnosis than white women.
Lawson et al6 extended this research in a population-based study of African-Americans living in Tennessee. They found that African-Americans constituted 16% of the state’s population but 48% of psychiatric inpatients diagnosed with schizophrenia and 37% of psychiatric outpatients.
CONSEQUENCES OF INACCURATE DIAGNOSIS
Differentiating between schizophrenia (Box 1) and a psychotic mood disorder (Box 2) is more than a semantic exercise. Schizophrenia implies a chronic, unremitting, debilitating illness that worsens over time. Though this perception of schizophrenia is not entirely accurate, in clinical practice its diagnosis imparts a bleak prognosis that may lower the clinician’s expectations for the patient.7
Schizophrenia misdiagnosis also may lead the psychiatrist to rely excessively on antipsychotics, rather than attempting thymoleptic and psychotherapy trials. Studies suggest that African-American patients are more likely than similar white patients to receive antipsychotics4,8,9 and less likely to receive psychotherapy.5,10
Reasons why African-Americans are often misdiagnosed with schizophrenia remain unclear but probably include four contributing factors:
- differences in symptom presentation compared with whites
- failure by clinicians to identify affective symptoms in African-Americans
- minority patients’ wariness when dealing with health services
- and racial stereotyping.
DIFFERENCES IN SYMPTOM EXPRESSION
African-American patients with mood disorders or schizophrenia are more likely than are similar white patients to complain of auditory hallucinations.11-13 For example, Strakowski et al14 examined 330 patients with nonaffective and psychotic diagnoses in a study that was used to develop DSM-IV criteria for schizophrenia. Auditory hallucinations were rated as more severe in African-American than in similar white patients.
Major depressive episode with psychotic features: Characteristic symptoms
MAJOR DEPRESSIVE EPISODE
Five or more of the following symptoms present during the same 2-week period and representing a change from previous functioning; must include either depressed mood or loss of interest or pleasure.
- Depressed mood
- Markedly diminished interest or pleasure
- Significant weight loss
- Insomnia or hypersomnia
- Psychomotor agitation or retardation
- Feelings of worthlessness or excessive guilt
- Diminished ability to concentrate
SEVERE MAJOR DEPRESSION WITH PSYCHOTIC FEATURES
Delusions or hallucinations whose content is entirely consistent with the typical depressive themes of personal inadequacy, guilt, disease, death, nihilism, or deserved punishment
Delusions or hallucinations whose content does not involve typical depressive themes. Includes symptoms such as persecutory delusions, thought insertion, thought broadcasting, and delusions of control
African-American patients also are more likely than whites to exhibit so-called Schneiderian first-rank symptoms of schizophrenia,15 including:
- delusions of thought broadcasting or insertion
- auditory hallucinations of voices conversing about the patient in the third person.
These symptoms were once used to diagnose schizophrenia, but their lack of specificity has been well documented.2,16 First-rank symptoms of schizophrenia depend on the specific form of the hallucination or delusion, are likely to be influenced by a patient’s culture, and may be misleading in multicultural populations. Though first-rank symptoms now occupy a minor role in U.S. diagnostic systems, they might continue to sway clinicians—even when using structured diagnostic interviews—to inappropriately diagnose schizophrenia in lieu of affective disorders in minority patients.15
To extend this finding, our group16 studied rates and severity of affective and psychotic symptoms—particularly first-rank symptoms—in 100 patients with psychotic mania who met DSM-III-R criteria for bipolar disorder (80%) or schizoaffective disorder, bipolar type (20%) as determined by structured diagnostic interview. No differences in affective symptoms between African-American and white patients were seen. African-Americans were more likely to endorse auditory hallucinations and to report severe auditory hallucinations of voices commenting on their behavior—the only first-rank symptom on which they differed from whites.
Though their affective symptoms were similar, African-Americans were significantly more likely than whites to have been diagnosed with a schizophrenia-spectrum disorder. Because misdiagnosis of African-Americans could not be explained by psychotic symptoms—which were as severe as those of white patients—these findings suggest other mechanisms were at work.
UNIDENTIFIED AFFECTIVE SYMPTOMS
Underidentification of mood disorders in African-American patients may also lead to over-diagnosis of schizophrenia. In a sample of 99 patients, colleagues and I 17 compared clinical diagnoses made in a psychiatric emergency service with those by research investigators using a structured clinical interview. Reasons for diagnostic differences were identified and divided into two categories:
- the same symptoms were recorded but applied differently to diagnostic criteria (criterion variance)
- different information was recorded, which led to diagnostic discrepancies (information variance).
Differences occurred significantly more often in African-American than in white patients, but only information variance was associated with ethnicity. This suggests that clinicians are less likely to elicit appropriate information from African-American than from white psychiatric patients. The fact that researchers obtained this information during diagnostic interviews suggests that the patients could provide it when given appropriate prompts. Specifically, affective symptoms were less likely to be elicited by clinicians than by researchers.
Minority patients, when interacting with clinicians of the majority population, may project “protective wariness.”18 Specific behaviors include hesitancy or reluctance to fully engage with the care provider as a precaution against being exploited or harmed. Cultural misunderstandings 19 and patient concerns about past reports of minorities receiving substandard or unethical health care20 may contribute to this behavior.
Whaley21 compared nonpathologic distrust and paranoia in 404 community-living African-Americans and whites. Some were healthy, and some had diagnoses of schizophrenia or depression. African-Americans—particularly those with psychiatric disorders—showed higher levels of distrust than whites. Distrust was also associated with depression in African-Americans but not in whites. Whaley concluded that:
- depressed African-Americans may exhibit more distrust toward clinicians than do whites
- this distrust puts African-Americans at risk of being perceived as paranoid and being misdiagnosed with paranoid schizophrenia.
Remedial actions to avoid ethnic bias in diagnosing schizophrenia
Failure to recognize differences in symptom expression
Become familiar with ethnic differences in how patients describe symptoms
Failure to elicit affective symptoms
Incorporate structured interviews or rating scales into the clinical assessment
Misinterpreted protective wariness
Clarify the patient’s degree of suspicion; consider this in the historical context of abuses toward minorities by majority populations
Covert and overt stereotyping and cultural insensitivity
Review practice patterns
Though Whaley did not report differences in distrust between African-American men and women, others have noted that distrust of health providers may be more common in minority men.18
Compared with similar white men, African-American men with mental disorders are more likely to be:
- referred for mental health care through social and legal—rather than medical—systems and to be involuntarily committed
- perceived as violent—even though controlled research suggests they are not. This misperception can lead to excessive medication and restraints.22
Differential treatment of African-American men may create a cycle of distrust, hostility, and additional inappropriate treatment. Together, these factors may increase the risk that African-American men will be misdiagnosed with schizophrenia.
Past racism in biomedical and psychiatric practice and research has been documented23,24 and more recently reviewed by Lawson.19 Historically, African-Americans were perceived to have a “primitive psychic” nature that was thought to be more susceptible to schizophrenia than depression. 19 Whether these or similar racist stereotypes continue to inject ethnic bias into clinical assessment requires further study.
WHERE DO WE GO FROM HERE?
Although research into methods to eliminate ethnicity bias is sparse, the work reviewed in this article suggests ways that psychiatrists can minimize this problem (Table).
Obtain comprehensive information. Use structured interviews, such as the Structured Clinical Interview for DSM-IV (SCID), and rating scales, such as the Hamilton Depression Scale, which require clinicians to ask about all types of symptoms, particularly affective symptoms.
Review treatment records. Review your practice patterns for evidence of schizophrenia over-diagnosis in African-Americans or other ethnic groups. Examine ethnic differences in legal referrals or use of restraints or seclusion, which may indicate an ethnic bias in how threats are perceived. Only by being aware of bias can one correct it.
Become familiar with cultural and ethnic differences in idioms of distress. Specifically, review research in cultural psychiatry to identify potential differences among cultural groups in how they describe psychiatric symptoms. Talk with colleagues or friends from other cultural groups, and read literature from different ethnic perspectives to increase your cultural sensitivity.
Consult with psychiatrists with expertise in cultural variability of clinical presentation when the diagnosis or threat assessment seems unclear. Consultation is recommended if a patient’s diagnosis is uncertain or if you detect bias in your practice.
These interventions require clinicians to become familiar with psychosocial differences in how patients of various cultural and ethnic groups express psychiatric symptoms. With this understanding, we can better engage wary patients, obtain valid information, and improve clinical practice and patient outcomes.