Major depression is a serious public health problem among older adults in the United States, but tends to affect ethnic groups differently, finds new research led by a Michigan State University scholar.

According to a survey of nearly 2,000 people aged 50 and older, whites and blacks of Caribbean descent experience much higher rates of major depression than African-Americans.

Amanda Toler Woodward, lead investigator on the study and MSU associate professor of social work, said the findings, taken as a whole, suggest major depression among older people is worse than many believe and has serious implications as the massive baby boomer generation ages.

Elderly people often have other health and mental issues that make it difficult to diagnose and treat major depression, Woodward said. In addition, there is a dearth of clinicians trained in geriatric mental health.

"It is clear that major depression is a significant public health issue among older people," said Woodward, whose study appears in the research journal Anxiety and Depression.

The study examined rates of major depression among three ethnic groups - whites, African-Americans and black Caribbeans- making it the first comprehensive examination of major depression among older blacks.

Specifically, the researchers found:

  • About 24 percent of whites aged 50 and older experienced major depressive symptoms at least once during their lifetime, and 9 percent experienced major depression in the previous 12 months.
  • About 17 percent of older African-Americans experienced major depression during their lifetime, with 7 percent experiencing major depression in the previous 12 months.
  • About 23 percent of older black Caribbeans experienced major depression during their lifetime, and 15 percent experienced major depressive symptoms in the previous 12 months.

While the study didn't measure why black Caribbeans had significantly higher rates of major depression than African-Americans, Woodward said it may have to do with negative experiences related to immigration such as being separated from family and friends and adapting to U.S. culture.

The number of black Caribbean immigrants in the United States has doubled in the past decade, to more than 3 million.

"This data shows that black Caribbeans and African-Americans are not as similar as one may think, and when we're thinking about diagnoses and treatment we shouldn't lump them together," Woodward said.

Older black men of Caribbean descent reported much higher rates of major depression than older black women of Caribbean descent. The runs counter to the other ethnic groups - whites and African-Americans - which saw women report higher rates of major depression.