African-American women with depression symptoms have higher chances of developing asthma, a latest research suggests.

Researchers at the Stone Epidemiology Center (SEC) at Boston University studied 31, 848 African-American women between 1999 and 2011. They were previously part of Black Women's Health Study (BWHS). They answered questionnaires with regard to 20 symptoms every two years, (e.g., "I felt depressed," I felt lonely," "I could not get going")

The study results showed that women who had higher levels of depressive symptoms had a higher rate of adult-onset asthma. The risk doubled for women with high levels of depressive symptoms in comparison to women from the lower group. Women in the highest group had a depression score equal to or above 33 and women in the lowest group had scores below 16.

The researchers also found that asthma rates were 2.8 times higher in women with scores equal to or above 16.

"Our results are consistent with positive findings from three previous studies of depressive symptoms and asthma incidence conducted in smaller and primarily white populations," said Coogan according to Medical Xpress. "The hypothesized mechanism linking depressive symptoms to asthma incidence is depression-related stress and its physiological consequences, particularly effects on the immune system and the airways. Given the high prevalence of both asthma and of depression in women, the association is of public health importance."

The researchers stated that they did not find a cause-and-effect relationship. However, they advised that  African-American women take preventive measures for depression. The study was published in Annals of Allergy, Asthma & Immunology.