THURSDAY, Nov. 30 (HealthDay News) -- Asian immigrants in the United States have lower rates of mental health problems than people, including those of Asian descent, who were born in the country, a new study finds.

For example, the study found that American-born women are twice as likely to have a depressive disorder as Asian-born women living in the United States.

The researchers interviewed nearly 2,100 native-born or immigrant Asian Americans, 18 and older, about their history of a number of mental health problems: depression, anxiety, phobias, eating disorders, substance and alcohol abuse, and post traumatic stress disorder.

"Roughly 48 percent of Americans will have some kind of lifetime disorder. In our study, less than one in four Asian-American immigrants will have a disorder. However, that won't necessarily be the case for their children and grandchildren. If trends continue, rates for them will go up, and that suggests that more investment is needed for prevention programs," study lead author David Takeuchi, a sociologist and social work professor at the University of Washington, said in a prepared statement.

Other findings from the study:

• There were no significant differences among the main Asian immigrant groups in the United States -- Chinese, Filipinos and Vietnamese.
• Among Asian men, those born elsewhere are less likely to have a substance abuse problem than those born in the United States.
• Asian immigrants who arrived in the United States as elementary school-age children have an easier time learning English than older children but are more likely to develop a substance abuse problem.

Takeuchi said this study raised issues that warrant further investigation. For example, he'd like to compare the mental health circumstances of immigrants who voluntarily migrate and those who are refugees.

"Someone who is a voluntary immigrant doesn't typically suffer the severe trauma that a refugee who is fleeing persecution or war does," Takeuchi said.

He also wants to investigate how discrimination impacts the mental health of Asian Americans.