Socially disadvantaged racial and ethnic groups in the United States, such
as African Americans and Hispanics, have a lower lifetime risk of psychiatric
disorders but a higher likelihood that those disorders will persist, compared
with non-Hispanic whites, said a report based on data from the National
"In both cases, these differences are not explained by differences in
socioeconomic status and are generally consistent across subgroups of the
population," wrote Joshua Breslau, Ph.D., of the department of health
care policy at Harvard Medical School, and colleagues. If replicated, the
findings could help illuminate the causes linking social position and mental
Separating prevalence and persistence is important, said the authors.
Lifetime prevalence reflects causal factors occurring before the onset of
mental illness that are best addressed through primary prevention, they
reported in the March issue of Psychological Medicine."
Differences in persistence, on the other hand, can potentially be
addressed through improvement in quality and accessibility of mental health
Looking at data from the intersection of ethnicity and health marks a
helpful step forward, said Altha Stewart, M.D., president of the American
Psychiatric Foundation and former chair of APA's Council on Social Issues and
Many people fear that even discussing these issues will raise accusations
of racism, she said.
"We need a scientific basis if we're to reduce disparities,"
said Stewart in an interview. "We're not comfortable talking about race,
but we must be able to talk about it to improve the systems of care.
Generating the dialogue is the first step in improving health care across
racial and ethnic groups."
The researchers studied data from a subsample of the National Comorbidity
Survey, carried out from 1990 to 1992. Of the 5,657 individuals in the
subsample, 9 percent were Hispanic, 12 percent were non-Hispanic blacks, and
78 percent were non-Hispanic whites. This cohort included all respondents who
screened positive for psychiatric disorders on the Composite International
Diagnostic Instrument, plus a random sample of control subjects.
"Persistence" was defined as onset of a disorder at least two
years prior to the interview and its presence in the 12 months prior to the
For 12-month prevalence, the researchers found few differences among the
three ethnic groups studied. Non-Hispanic blacks did have significantly lower
prevalence of substance use disorder and any mental disorder, compared with
However, for lifetime prevalence, both Hispanics and non-Hispanic blacks
had a lower prevalence of mood, anxiety, substance abuse, and any mental
disorder, compared with non-Hispanic whites.
The results were statistically significant for six of the eight possible
comparisons. Only prevalence of any mental disorder among Hispanics (p=0.08)
and prevalence of anxiety among blacks (p=0.084), while trending in the same
direction, did not reach significance.
What might explain the lower prevalence of psychiatric disorders?
"There is in the psychological literature the concept of
`resilience,' that people who have suffered and survived are somehow better
able to manage in spite of their difficulties," suggested Stewart."
Or they may have a higher tolerance for abnormal behavior, or may avoid
coming into contact with the mental health system, possibly by seeking help
from nonmedical sources like ministers."
However, with regard to persistent disorders, six of the eight comparisons
showed that Hispanics or non-Hispanic blacks had higher 12-month prevalence
among lifetime cases, with five of the six comparisons reaching statistical
significance (p<0.01). Compared with whites, Hispanics had significantly
higher rates of mood, anxiety disorders, and any mental disorder, while blacks
had significantly higher rates of anxiety and any mental disorder. Blacks had
significantly lower rates of substance abuse disorders, Breslau noted.
Blacks had significantly higher odds ratios than whites for persistent mood
disorders (OR=1.79), for anxiety disorders (OR=1.51), and any disorder, once
socioeconomic status was controlled for. Hispanics had significantly higher
persistence of any disorder under the same conditions. Results were the same
when controlled for receipt of any mental health treatment.
"Compared with non-Hispanic whites, Hispanics and non-Hispanic blacks
tend to have a lower risk of having a psychiatric disorder in their lifetime,
but those who become ill tend to have more persistent disorders," the
They offered two interpretations of their conclusions. If prevalence and
persistence were connected through a single mechanism, the same mechanism
would both reduce the likelihood of disorders and make them more persistent
once they occurred. If this is true, the researchers said, little can be done
after the onset of illness, and only prevention can help these disadvantaged
However, Breslau and colleagues suggested that prevalence and persistence
should be viewed separately, as outcomes of different processes.
Factors—such as cultural patterns—in effect before the onset of
disorders reduce the risk of psychiatric disorders among disadvantaged
racial-ethnic minorities, while different factors operating at or after onset
contribute to persistence. That may open up other avenues for
"Based on this model, access to quality mental health treatment is a
possible cause of and remedy for disparities in persistence," the
An abstract of "Lifetime Risk and Persistence of Psychiatric
Disorders Across Ethnic Groups in the United States" is posted online at<http://journals.cup.cam.ac.uk/bin/bladerunner?REQUNIQ=1115652618&REQSESS=10713655&118000REQEVENT=&REQINT1=283268&REQAUTH=0>.▪