For years mental health experts have touted evidence of a substantial gender gap in depression, with statistics show that women disproportionately suffer from the mental health condition. But according to the findings of a new study, depression may be just as common in men, but widely underreported due to the less understood ways it manifests itself.

Statistics have previously shown that women were twice as likely as men to develop depression at some point in their life, with roughly one in five predicted to encounter the disorder. But a study conducted by researchers at the University of Michigan and Vanderbilt, published in the Journal of the American Medical Association on Wednesday, confirmed what some researchers have suspected for years; that mental health experts are likely missing out on crucial diagnostic criteria that could determine if men are depressed.

"When men are depressed they may experience symptoms that are different than what is included in current diagnostic criteria," Lisa A. Martin, Ph.D., and the study’s co-authors wrote. "If we can get men who have depression to recognize it in themselves and get treatment, that is really significant," Martin said.

Researchers identified several previously uncharted symptoms of depression in men, including anger, aggression, substance abuse, or activities with a high degree of risk like gambling or womanizing. When researchers accounted for those symptoms in a study of 3,310 women and 2,382 men, they estimated that approximately 26% of men and 22% women had, at some point, suffered from depression. Martin said that the study was the first to examine gender differences in diagnosing the disorder.

Furthermore, the National Institute of Mental Health notes on its website that “Many men do not recognize, acknowledge, or seek help for their depression,” because “they may be reluctant to talk about how they are feeling.”

Martin corroborated that claim, saying that circumstantial evidence suggested men were far less likely than women to seek help on their own. She said that clinicians she spoke to said complained that men often only appeared in their offices after having “been given ultimatums by their wives or their employers.”

"Paying attention to a couple of these other symptoms allowed men who didn't really meet the threshold of symptoms to be considered," Martin said. "Right now we're in an interesting place where clinicians and some research say we really need to pay attention to (unorthodox symptoms).”

Martin conceded that the study did not take into account stress from overworking, over exercising, or changes in sexual behavior. However, she said she hopes that it will lead to changes in how doctors diagnose the condition, with advertising equally targeting men along with women.

"It doesn't do us a lot of good to know more men get depression more than we thought if we can't get them through the door to get help," she said. "How we advertise for support groups and how we do outreach to people needs to change.”