(Ivanhoe Newswire) -- You can inherit many things from your family, but now a new study reveals chronic major depression may be added to that list.

Researchers report people are more than twice as likely to suffer severe chronic depression if they have a close relative who was diagnosed with it before the age of 31. Furthermore, first-degree relatives of patients diagnosed with chronic major depression before the age of 13 have a six-to-one chance of being diagnosed.

Researchers from Johns Hopkins University in Baltimore studied 638 men and women diagnosed with early-onset major depression and more than 2,100 of their first-degree family members. A first-degree family member includes a sibling, parent or child.

Researchers report patients with chronic depression are 17.6-percent more likely to have relatives with chronic depression than patients who have non-chronic depression. This means, write the authors, that more severe cases of depression are likely to have a familial link.

While study authors report this finding suggests a possible genetic link, they caution that the results could also point to environmental factors as well such as a loss of a parent at an early age or abuse. However, researchers are now recruiting people for a larger study at Johns Hopkins and five other sites.

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SOURCE: American Journal of Psychiatry, 2006; 163:1-7