Migrants from Mexico have increased risk of depression and anxiety disorders

People who migrate to the United States from Mexico have a significantly higher risk of developing depressive or anxiety disorders than family members of migrants who remain in Mexico, according to a report in the April issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

'About 12 million people living in the United States in 2007 were born in Mexico, constituting approximately 30 percent of the U.S. foreign-born population, 25 percent of the U.S. Hispanic population, and 10 percent of the Mexican-born population on both sides of the Mexico-U.S. border,' the authors write as background information in the article. 'Mental health researchers have hypothesised that adverse social experiences inherent in the migration process have a negative effect on mental health in this population.'

Joshua Breslau, Ph.D., Sc.D., of the University of California, Davis, School of Medicine, Sacramento, and colleagues combined data from surveys conducted separately in Mexico and the United States to test the hypothesised increase in risk for depressive and anxiety disorders among Mexican migrants after arrival in the United States. They compared a sample of Mexican-born migrants (259 men and 295 women) after their arrival in the U.S. with a sample of non-migrants in Mexico (904 men and 1,615 women) on their risk for first onset of a depressive or anxiety disorder. Depressive disorders included major depression and dysthymia (a less severe type of depression with long-term, chronic symptoms that are not disabling). Anxiety disorders included social phobia, panic disorder, post-traumatic stress disorder, and generalised anxiety disorder (GAD).

'After arrival in the United States, migrants had a significantly higher risk for first onset of any depressive or anxiety disorder than did non-migrant family members of migrants in Mexico,' the authors report.

The elevated risk among migrants was restricted to younger age groups - those age 18-25 years and 26-35 years at the time of their diagnostic interview. The strongest association between migration and first onset of a depressive or anxiety disorder was found in those ages 18-25.

'The finding that migrants are at higher risk for onset of depressive and anxiety disorders after migration compared with family members of migrants who remained in Mexico provides the first direct evidence that experiences as a migrant might lead to the onset of clinically significant mental health problems in this population,' the authors write. 'In particular, migrants were at higher risk for depressive disorders, inclusive of major depression and dysthymia, GAD, and social phobia.'

'The finding that elevation in risk for depressive and anxiety disorders occurs among recent birth cohorts of Mexican migrants may help guide future research by locating the effect of migration within the particular experiences of this subpopulation,' they conclude.