CHICAGO --- Domestic violence occurs at least as frequently, and likely even more so, between same-sex couples compared to opposite-sex couples, according to a review of literature by Northwestern Medicine® scientists.

Previous studies, when analyzed together, indicate that domestic violence affects 25 percent to 75 percent of lesbian, gay and bisexual individuals. However, a lack of representative data and underreporting of abuse paints an incomplete picture of the true landscape, suggesting even higher rates. An estimated one in four heterosexual women experience domestic abuse, with rates significantly lower for heterosexual men.

“Evidence suggests that the minority stress model may explain these high prevalence rates,” said senior author Richard Carroll, associate professor in psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine and a psychologist at Northwestern Memorial Hospital. “Domestic violence is exacerbated because same-sex couples are dealing with the additional stress of being a sexual minority. This leads to reluctance to address domestic violence issues.”

The review was published Sept. 4 in the Journal of Sex & Marital Therapy. The first author is Colleen Stiles-Shields, a student in the clinical psychology Ph.D. program at Feinberg.

Domestic violence -- sometimes called intimate partner violence -- is physical, sexual or psychological harm occurring between current or former intimate partners. Research concerning the issue began in the 1970s in response to the women’s movement, but traditionally studies focused on women abused by men in opposite-sex relationships.

“There has been a lot of research on domestic violence but it hasn’t looked as carefully at the subgroup of same-sex couples,” Carroll said. “Another obstacle is getting the appropriate samples because of the stigma that has been attached to sexual orientation. In the past, individuals were reluctant to talk about it.”

Of the research that has examined same-sex domestic violence, most has concentrated on lesbians rather than gay men and bisexuals.

“Men may not want to see themselves as the victim, to present themselves as un-masculine and unable to defend themselves,” Carroll said.

He suggests that homosexual men and women may not report domestic violence for fear of discrimination and being blamed for abuse from a partner. They also may worry about their sexual orientation being revealed before they’re comfortable with it.

Mental health services for people involved in abusive same-sex relationships are becoming more common, but this population still faces obstacles in accessing help, reports the paper.

“We need to educate health care providers about the presence of this problem and remind them to assess for it in homosexual relationships, just as they would for heterosexual patients,” Carroll said. “The hope is that with increasingly deeper acceptance, the stress and stigma will disappear for these individuals so they can get the help they need.”

-Nora Dunne, content specialist at the Feinberg School of Medicine, is the author of this story.