Immigration blues: born in the USA: mental-health deficit.

Immigrants to the land of the free may, simply by moving here, end up taxing the mental health of their U.S.-born offspring. A wide array of psychological disorders occurs at a much higher rate among Mexican Americans born in the United States than among Mexican Americans born in Mexico, a national study finds. A nearly equivalent disparity separates foreign-born from U.S.-born non-Hispanic whites, conclude epidemiologist Bridget F. Grant of the National Institute on Alcohol Abuse and Alcoholism in Bethesda, Md., and her coworkers.

The new findings indicate that the stress encountered by new immigrants, often a function of poverty and cultural unfamiliarity, doesn't provoke psychiatric disorders. At least for foreign-born Mexican Americans, access to traditional avenues of psychological and financial support from their extended families, whether in Mexico or the United States, may partly protect mental health, the researchers say.

Their results, published in the December Archives of General Psychiatry, add to evidence that the mental and physical health of immigrants from various countries and their children deteriorates with increasing assimilation to a U.S. lifestyle (SN: 9/19/98, p. 180).

"It's time to ask hard questions about why the physical and mental health of immigrants to the United States has been declining over the last few decades," remarks Arthur M. Kleinman, a psychiatrist and anthropologist at Harvard University.

Grant's team analyzed data from psychiatric interviews conducted throughout the United States in 2001 and 2002 with 43,093 people, age 18 or older. That total included 4,558 Mexican Americans, about equally split between foreign and U.S. born. Of the more than 24,000 non-Hispanic whites in the study, 1,541 were foreign born.

Among U.S.-born participants, about 48 percent of Mexican-Americans and 53 percent of non-Hispanic whites had developed at least one psychiatric disorder at some time. The conditions included alcohol and drug disorders, major depression, a mild form of depression called dysthymia, mania, panic disorder, social phobia, and general anxiety disorder.

Among foreign-born participants, psychiatric disorders had afflicted only about 29 percent of Mexican Americans and 32 percent of non-Hispanic whites.

In the most striking disparity, illicit drug disorders had occurred in 12 percent of U.S.-born Mexican Americans, compared with 1.7 percent of their foreign-born counterparts.

Even transported to another country, traditional Mexican-American culture apparently bolsters psychological fitness in poorly understood ways, the scientists assert. Although foreign-born Mexican Americans displayed only slightly lower rates of psychiatric disorders than non-Hispanic white immigrants did, Mexican Americans born in the United States enjoyed a clear mental health advantage over U.S.-born non-Hispanic whites, the researchers say.

Low rates of psychiatric disorders among foreign-born Mexican Americans may partly reflect the movement of migrant workers back and forth between Mexico and the United States, Kleinman notes.

Whatever factors influence the mental-health measures in the new report, Grant's team has tapped into a burgeoning phenomenon. Census Bureau data show that the nation's immigrant population, legal and illegal, reached a record of more than 34 million in March 2004, an increase of 4.3 million since 2000. Mexico accounts for nearly one-third of new U.S. immigrants.