Overdiagnosis of Schizophenia Said to Be Persistent Among Black Patients

Schizophrenia, along with bipolar disorder and posttraumatic stress disorder, continue to be overdiagnosed among African Americans, reflecting cultural factors that influence patient presentation as well as clinical decision-making.

So asserts William Lawson, M.D., Ph.D., chair of the Department of Psychiatry and Behavioral Sciences at Howard University Health Sciences. Lawson has written more than 100 publications concerning severe mental illness and its relationship to psychopharmacology, substance abuse, and racial and ethnic issues and has a long-standing concern about ethnic disparities in mental health treatment.

He is the princial investigator for five grants from the National Institutes of Health to study diagnosis and treatment of comorbid mental and substance use disorders in African Americans and other ethnic minorities.

At APA’s 2014 Institute on Psychiatric Services in November, he delivered the Solomon Carter Fuller Award Lecture in which he spoke at length about health disparities and cultural factors that influence and contribute to those disparities.

He focused in particular on the overdiagnosis of schizophrenia among black individuals. He noted that the phenomenon has been shown in multiple studies and that cultural factors in diagnosis have received considerable publicity—particularly with the publication of DSM-5, which contains a special section on culture and diagnosis. Nevertheless, it has been a stubborn and persistent phenomenon. “The overdiagnosis of schizophrenia is still very much with us,” he said.

He presented data from a study published in JAMA Psychiatry in June 2012, which was designed to determine whether African Americans would continue to exhibit significantly higher rates of clinical diagnoses of schizophrenia after controlling for age, sex, income, site, and education, as well as the presence or absence of serious affective disorder, as determined by experts blinded to race and ethnicity.

Lawson and colleagues found that African Americans elicited significantly higher rates of clinical diagnoses of schizophrenia than non-Latino white subjects, even after controlling for covariates such as serious affective disorder.

That study also found that despite these diagnostic differences, African-American and white subjects did not differ significantly in blinded expert ratings of affective symptoms, but that African-American subjects did receive higher ratings of psychosis. “These observations suggest that in African-American subjects, psychotic symptoms may be overvalued by clinicians, skewing diagnoses toward schizophrenia-spectrum conditions, even with similar levels of affective symptoms as white subjects,” the researchers concluded.

Moreover, Lawson said, “cultural mistrust” on the part of African Americans—which may be manifest in symptoms that mimic paranoia—may be related to the overdiagnosis of schizophrenia. In a study presented at a poster session at the 2012 Institute on Psychiatric Services, Lawson and colleagues used a measure of cultural mistrust to examine the relationship between mistrust and psychopathology in 244 African-American patients with severe affective disorders.

They found that the cultural mistrust inventory is significantly related to total psychosis, hallucinations/delusions, and depression, but not to mania or bizarre behavior. Cultural mistrust is presumed to be the result of negative racial experiences or awareness of historical antecedents, and the findings provide limited support to the idea that there is a cultural basis for the greater risk of psychosis diagnoses in African Americans, which may account for the overdiagnosis of schizophrenia.

At the 2014 institute, Lawson also presented evidence showing that African Americans were significantly less likely to receive lithium and SSRI antidepressants and significantly more likely to receive first-generation antipsychotics and any antipsychotic than were patients of other racial groups.

In comments to Psychiatric News, Annelle Primm, M.D., M.P.H., APA deputy medical director and director of the Division of Diversity and Health Equity, said Lawson’s work as a clinician, researcher, scholar, and policy adviser “has placed him at the forefront of the field as an expert on community psychiatry, substance use disorder care, and comorbidities such as HIV infection in African Americans and other medically underserved groups. I applaud his efforts to enlighten psychiatrists about the big-picture issues as well as the intricate nuances of assessment, diagnosis, and treatment of mental disorders in African Americans.”

She added, “Regarding the overdiagnosis of schizophrenia in African Americans, Dr. Lawson’s work has helped us understand that some clinicians have had a low threshold for consideration of psychotic symptoms as a proxy for schizophrenia, even though these symptoms are also seen in mood disorders, and schizophrenia should be a diagnosis of exclusion. Culturally driven ‘healthy paranoia,’ which describes a type of suspiciousness regarded as a survival skill in African Americans, can be mistaken for a psychotic symptom, which may become fodder for misdiagnosis of schizophrenia in unenlightened clinicians.” ■