More than 40 percent of women surveyed in the Seattle area reported they had been physically or psychologically abused by their husbands, dates or boyfriends, researchers said on Wednesday.

And a second study showed that women who have been slapped, kicked or otherwise abused were four times more likely to report severe depressive symptoms and three times more likely to report fair or poor health.

The researchers, who say their study is a snapshot but suggests a national trend, were surprised at the numbers.

“This is an epidemic,” said Dr. Robert Thompson of the Seattle-based Group Health Center for Health Studies, who led one study.

“But it flies under the radar, because of the stigma and shame associated with it - as well as the fear that many health care providers have of opening what some call a ‘Pandora’s Box’ of difficult problems that they are unsure how to address,” Thompson added in a statement.

For their study, Thompson and colleagues interviewed a random sample of more than 3,400 women members of a Seattle health maintenance organization.

They found 44 percent of the women, aged 18 to 64, had suffered some form of what they call “intimate partner violence.” Most reported more than one type - for example, physical violence and verbal threats.

Intimate partner violence “harms women’s physical and mental health even more than do other common conditions, such as back pain and even several forms of cancer,” said Amy Bonomi of the Group Health Center for Health Studies, who wrote the second study.

Her team found that women who were recently abused were four times as likely as other women to report symptoms of severe depression and nearly three times as likely to report poor or fair health.

The studies, funded by the U.S. federal Agency for Healthcare Research and Quality, mesh with previous estimates that show anywhere between 25 to 50 percent of women may have experienced abuse.

But the studies focused on women with health insurance, who tend to be older and have higher incomes and more education than average.

Of the women who were abused, 13 percent said it had persisted for more than 20 years.