Psychosis May Be Overdiagnosed in Blacks
By John Gever, Senior Editor, MedPage Today May 09, 2012
Reviewed by Zalman S. Agus, MD; Emeritus Professor, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner
- Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
- Rates of clinical diagnoses of schizophrenia in African Americans are uniquely elevated among major U.S. ethnic groups. This study suggests that there is a cultural basis for the greater risk of psychosis in African Americans, which may account for overdiagnosis of schizophrenia.
PHILADELPHIA — Suspicion of white-dominated institutions and society at large among African Americans may translate into overdiagnosis of schizophrenia, a researcher said here.
Identification of total psychosis and some specific schizophrenia symptoms in black patients significantly correlated with their scores on an index of cultural mistrust, reported William Lawson, MD, PhD, of Howard University in Washington, D.C., at the American Psychiatric Association’s annual meeting.
He said the findings provide “limited support” to the idea that cultural factors contribute to the previously reported higher risk for schizophrenia diagnoses in African Americans.
At the same time, the findings might also help explain findings that bipolar disorder is less common in blacks than in whites, perhaps because it is underdiagnosed.
The study by Lawson and colleagues was a secondary analysis of data from a study of 610 psychiatric inpatients from six geographically diverse academic medical centers.
This analysis focused on 244 African-American patients with severe affective disorders. In addition to the Cultural Mistrust Scale, the patients were evaluated with standard psychometric instruments including the Diagnostic Interview for Genetic Studies, the Montgomery-Asberg Depression Scale, the Young Mania Rating Scale, and the Scale for Assessment of Positive Symptoms. These scales were administered by trained masters’- and PhD-level interviewers.
About 40% of the patients were male. Mean age was about 34 with a range of 18 to 53. Educational level was about evenly split among less than high school, completed high school, and some college experience. However, three-quarters had an annual income of $15,000 or less.
The cultural mistrust index was developed in 1981 specifically to measure African-Americans’ suspicions about white-dominated society. It asks respondents to rate their level of agreement or disagreement with a series of statements such as, “blacks should be suspicious of whites who want to be friendly” and “white policemen will slant a story to make a person look guilty.”
Although 40 participants did not complete the cultural mistrust inventory, their scores were imputed from the available data using a Markov chain Monte Carlo method, the researchers indicated.
The primary result was the cultural mistrust scores were significantly correlated (P<0.05) with the following psychiatric findings after adjusting for demographic variables:
- Total psychosis score: r=0.15
- Hallucinations/delusions score: r=0.14
- Depression score: r=0.20
Other symptoms such as mania and bizarre behavior were not correlated with the mistrust scores.
Lawson told MedPage Today that some of the questionnaire items used to evaluate psychosis and schizophrenia — especially those having to do with paranoia — have special resonance among many African Americans.
These include questions such as “do people follow you?” and “are people out to get you?,” he said. For many blacks, affirmative answers are grounded in reality — either their own personal experiences or their cultural teachings.
He suggested that more research is needed to develop diagnostic systems that are “less culture-bound.”
In the meantime, clinicians need more training in cultural factors and how they may influence diagnostic methods.
Lawson said he and his colleagues were planning to conduct a similar analysis with other racial and ethnic minorities.
The study was funded by the National Institute of Mental Health.
Lawson reported that he had no relevant financial interests.