Mexican-American and non-Hispanic white immigrants both have a lower
prevalence of psychiatric disorders than their U.S.-born counterparts, but
Mexican Americans born in the United States retain that advantage over
non-Hispanic whites born here, according to a study by researchers at the
National Institute on Alcohol Abuse and Alcoholism (NIAAA).
"Acculturation is bad for both Mexican Americans and non-Hispanic
whites, but it's not as bad for Mexican Americans," said lead researcher
Bridget Grant, Ph.D., Ph.D., chief of the Laboratory of Biometry and
Epidemiology in the intramural research program of the NIAAA.
Grant and her colleagues examined data from NIAAA's 2001-02 National
Epidemiological Survey on Alcohol and Related Conditions (NESARC), a
face-to-face survey of 43,093 persons aged 18 and older. This included 7,995
Hispanics Americans of whom 4,558 were Mexican Americans. Participants
answered questions about alcohol or drug use disorders, mood disorders, and
anxiety disorders. A Spanish version of the survey and Spanish-speaking
interviewers were available to respondents. About 15 percent requested to be
interviewed in Spanish.
The new report makes use of a large dataset and reinforces earlier studies
showing the significant role of culture in protecting immigrant groups from
the risks of psychiatric illness, said Sergio Aguilar-Gaxiola, M.D., Ph.D., a
professor of psychology at California State University, Fresno. Yet
Aguilar-Gaxiola, who has worked on other studies of Mexican-American mental
health, has some reservations about the NESARC survey's methods.
"We don't know the percentage of Spanish speakers or the linguistic
composition of the NESARC cohort," said Aguilar-Gaxiola, adding that
more than 50 percent of respondents in his own Mexican-American Prevalence and
Services Survey (MAPSS) preferred to be interviewed in Spanish.
Grant said that the MAPSS study was more geographically focused (in central
California), but that across the United States a smaller percentage of
respondents would ask for interviews in Spanish.
Earlier research indicated that immigrants often have better health status
than the native-born population they join. The current study differs in
several ways from previous epidemiological work on Mexican Americans, said
"In prior work, the samples were too small, or Mexican Americans were
studied without a comparison group, or else foreign-born and U.S.-born
Mexicans were compared with the entire non-Hispanic white population,"
she said. The latter confounded race/ethnicity and immigration status.
The NESARC survey found that prevalence rate of any psychiatric disorder
was 36.7 percent among all Mexican Americans and 51.2 percent among all
non-Hispanic white Americans. For foreign-born Mexican Americans, the rate was
28.5 percent, and for foreign-born non-Hispanic whites, 32.7 percent.
U.S.-born Mexican Americans had a prevalence rate of 47.6 percent, compared
with 52.6 percent for whites. The study used DSM-IV criteria for mood
and anxiety disorders.
Several explanations have been offered for health differences between
foreign-born and U.S.-born populations of the same ethnic background. The"
social stress" hypothesis says that poverty and adapting to a new
culture should lead to worse health among immigrants compared with the native
born. However, both the NESARC data and previous research have undermined
support for this concept.
"Usually lower socioeconomic status produces increased illness, but
Grant et al. show just the opposite," said Javier Escobar, M.D., a
professor and chair of the department of psychiatry at the Robert Wood Johnson
Medical School in Piscataway, N.J.
A second model argues that people with better mental health are more likely
to emigrate, and their less-healthy compatriots are the ones who stay behind
in the old country.
However, earlier studies by researchers such as Aguilar-Gaxiola, William
Vega, Ph.D., of Robert Wood Johnson Medical School, as well as those by other
researchers found that rates of psychiatric illness were similar among
foreign-born Mexican Americans and residents of Mexico City, undermining the
case for any selection effect. They contend that time spent living in the
United States was the key.
"Younger age of entry and longer residence in the United States were
associated with increased rates of psychiatric disorders," Vega
But Grant said she found no effect for length of stay in analyzing the
NESARC data. Immigration status alone doesn't determine risk for psychiatric
disorders, since U.S.-born Mexican Americans have a lower risk compared with
U.S.-born whites, said Grant. "Foreign-born Mexican Americans and
foreign-born non-Hispanic whites appear to share the lower risk status of
their national origins, but acculturation appears to have a deleterious effect
on their mental health," she said.
The negative effects of acculturation seem to apply more strongly to
non-Hispanic white immigrants, who lack some protective factors that buffer
the Mexican-American immigrants. Current thinking attributes this more to
culture than to stress or self-selection.
"The traditional Mexican family is more closely knit than most
non-Hispanic white families, with many extended family members who offer a
great deal of social and psychological support," said Grant.
Such support may come from cultural components like marriage or language.
Foreign-born Mexican American adults are more likely to be married (73
percent) than Mexican Americans born in the United States (55 percent),
according to Grant.
"Among the foreign-born, the longer they stay in the U.S., the higher
their divorce rate goes and the worse their mental state, while those who
retain Spanish as their mother tongue longer are more protected," said
"Immigrants are protected because they still have strong family
connections," agreed Escobar. But other social factors intrude into
their lives in subsequent generations. "For example, immigrant women
give birth to healthier babies than U.S.-born mothers because they are less
likely to smoke, have sexually-transmitted diseases, or use recreational
Substance abuse is, however, a potent new risk factor that predisposes
users to mental illness, he said. Drug use disorder rates for foreign-born
Mexican Americans (1.7 percent) are lower than for non-Hispanic white
immigrants (4.8 percent), but rates for U.S.-born Mexican Americans (12.0
percent) are close to those of U.S.-born whites (11.6 percent), according to
Psychological expectations may also change as populations assimilate, said
Escobar. Immigrants escaping the difficulties of their former countries arrive
with hopeful feelings about the United States, but become more vulnerable as
time passes. The native-born descendants of immigrants may have the security
of citizenship, but also experience discrimination, stresses of living in a
competitive society, and the erosion of family connections.
If the "selection" and "stress" models are now less
persuasive than the "cultural" model, both researchers and
clinicians should begin looking at the cultural patterns of ethnic subgroups,
according to Grant, Escobar, and Aguilar-Gaxiola. Do these same principles
apply to other Hispanic immigrant groups like Puerto Ricans or Cubans?
"The important thing is that now we have a model to test against
other immigrant groups," said Grant. Researchers can now look at each
ethnic group to look for the patterns, differences, and similarities within
cultures that raise or lower risks of psychiatric morbidity. The same insights
should be helpful for clinicians trying to understand and treat their
patients, as well.
Grant's research was supported by NIAAA with supplemental support from the
National Institute on Drug Abuse.
An abstract of "Immigration and Life-time Prevalence
ofDSM-IVPsychiatric Disorders Among Mexican Americans
and Non-Hispanic Whites in the United States" is posted online at<http://archpsyc.ama-assn.org/cgi/content/abstract/61/12/1226>.▪
Arch Gen Psychiatry