Bisexual women are more likely to suffer poor mental health and psychological distress than lesbians, according to a large survey from the United Kingdom.

Compared with lesbians, bisexual women were 64% more likely to report eating problems and 37% more likely to have deliberately harmed themselves than lesbians, after adjusting for confounding factors, the survey showed.

Bisexual women were also 26% more likely to report depressed feelings and 20% more likely to have suffered from anxiety, report the researchers from the London School of Hygiene and Tropical Medicine in an article published online January 13 in the Journal of Public Health.

"Disturbing" Results

Bisexual women were also less likely to be "out" to friends, family, and work colleagues and less likely to be in a relationship.

"Concealment of sexual orientation is known to be related to poorer mental health in sexual minority women, although the mental health benefits of disclosure may be mixed for bisexual women," the researchers write.

"Bisexual people are at particular risk of invisibility and marginalization from both gay/lesbian communities and mainstream society," senior author Ford Hickson, PhD, said in a news release.

"Although bisexual women in our study reported experiencing less sexuality-based discrimination than lesbians, this did not benefit their mental health. Mental health services should be aware of both the differences and the similarities in bisexual and lesbian women's mental health care needs, and tailor the services they provide accordingly," Dr Hickson adds.

The survey also showed that older bisexual women had more suicidal thoughts than younger bisexual women. Bisexual women were also more apt to report poor physical health and more likely to use marijuana or tranquilizers than lesbians.

"These disturbing results echo international findings on mental health differences between bisexual and homosexual people," lead author Lisa Colledge notes in the release.

"Although nonheterosexual women as a group have far poorer mental health than heterosexual women, bisexual women report even worse mental distress than lesbians. All women deserve equal chances of mental well-being and happiness, regardless of their sexuality. Homophobic prejudice is now widely and rightly condemned; specific stigma around bisexual identity needs to be similarly confronted," Colledge said.

Negative Social Attitudes

The researchers note that it is possible that poorer mental health in bisexual women (compared with lesbians) may be due to more negative social attitudes toward bisexuality compared with lesbian and gay identity. As a result, bisexual women may have a more negative attitude toward themselves and expect more social rejection, putting their mental health at risk.

The researchers add that their results differ from those of a similar UK survey conducted in 2003, which found no difference in psychological distress between bisexual women and lesbians. They think legal and social changes in subsequent years may have benefited lesbian women more than bisexual women.

The findings stem from the 2007 Stonewall UK Women's Health Survey. Participants included 937 bisexual women and 4769 lesbian women aged 14 years or older living in the United Kingdom.

The participants in the survey did not represent a random sample of the population and therefore may not be representative of all UK bisexual women and lesbians, the researchers note.

Also, because of its cross-sectional design, the study cannot establish that bisexual identity causes greater mental distress than lesbian identity, "despite substantial effect sizes, support from other research in different settings, analogous poor mental health findings in LG [lesbian/gay] vs heterosexual populations, and a plausible psychological mechanism."

The study had no commercial funding. The authors have disclosed no relevant financial relationships.

J Public Health. Published online January 13, 2015. Full text