As scientists continue to debate whether depression is hereditary, a new research published Wednesday suggests that people, whose parents and grandparents dealt with depression, are at a higher risk of having major depressive disorder.

In the U.S., depression is one of the most common mental disorders. Latest data provided by National Institute of Mental Health (NIMH) states that nearly 16 million adults in America aged 18 or older experienced at least one major depressive episode in 2014. About two of 100 children and eight out of 100 teenagers are likely to have serious depression, according to NIMH. The lifetime risk is about 17 percent.

Authors of the study published in JAMA Psychiatry Wednesday said that the findings can help identify people who can be benefited from early intervention.

For the research, Myrna M. Weissman, Ph.D., of Columbia University and New York State Psychiatric Institute examined 251 grandchildren with an average age of 18. They were interviewed an average of two times, their biological parents were interviewed an average of nearly five times and grandparents interviewed up to 30 years.

Researchers compared first two generations and found that grandchildren with depressed parents had twice the risk of major depressive disorder, increased risk for disruptive disorder, substance dependence, suicidal ideation or gesture and poorer functioning compared with people whose parents did not have depression. After studying the three generations, researchers found that grandchildren with both a depressed parent and grandparent had three times the risk of depression.

“In this study, biological offspring with two previous generations affected with major depression were at highest risk for major depression, suggesting the potential value of determining family history of depression in children and adolescents beyond two generations. Early intervention in offspring of two generations affected with moderate to severely impairing MDD [major depressive disorder] seems warranted,” according to the study.

However, the study authors cautioned of the limitations of the research, including its small sample size and a potential lack of what they called “generalizability” because of its composition.