Researchers at the Columbia University Mailman School of Public Health with colleagues at the Universities of Minnesota, Alabama at Birmingham, California at San Francisco and Harvard University found similar results when whites reported discrimination -- although 38 percent of whites report discrimination, compared to 89 percent of African-Americans.

The study, published in the American Journal of Epidemiology, also found African-Americans experiencing racial discrimination had more education, higher income, and a stronger social network than those reporting no racial discrimination. In contrast to African-Americans, whites reporting racial discrimination reported less education and lower income than did those who reported none.

"It is possible that use of a recreational drug helps to cope with life stress resulting from perceived unfair treatment because of one’s race/ethnicity," study leader Dr.Luisa Borrell of the Mailman School of Public Health said in a statement.