Holding hands Bisexual women are more likely to experience poor mental health and mental distress than lesbians, according to new research. 

The research, published in the Journal of Public Health, found that bisexual women were 64% more likely to report an eating problem and 37% more likely to have deliberately self-harmed than lesbians. They were also 26% more likely to have felt depressed and 20% more likely to have experienced anxiety in the previous year than lesbians.

Using data from the 2007 Stonewall UK Women's Health Survey, researchers from the London School of Hygiene & Tropical Medicine analysed responses from 5,706 bisexual and lesbian women living in the UK aged 14 or over. 

They found bisexual women were less likely to be ‘out’ to friends, family and work colleagues or to be in a relationship. Although bisexual women were less likely to experience sexuality-related discrimination from work, healthcare services, education and family than lesbians, they were more likely to experience discrimination from friends.

Study senior author Dr Ford Hickson, from the London School of Hygiene & Tropical Medicine, said: “Bisexual people are at particular risk of invisibility and marginalisation from both gay/lesbian communities and mainstream society. 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.” 

The authors also found that older bisexual women had more suicidal thoughts than younger bisexual women. Additionally, bisexual women were more likely to report poor physical health and more likely to use marijuana or tranquilisers than lesbians. 

Study lead author Lisa Colledge, who conducted the research at the London School of Hygiene & Tropical Medicine, added: "These disturbing results echo international findings on mental health differences between bisexual and homosexual people. Although non-hetrosexual 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 wellbeing and happiness, regardless of their sexuality. Homophobic prejudice is now widely and rightly condemned; specific stigma around bisexual identity needs to be similarly confronted." 

In the UK, the numbers of women identifying as lesbian and as bisexual are similar. However, only 16% of the survey participants were bisexual women. The study authors suggest this may be linked to bisexual women's reluctance to disclose their sexual identity. The authors add that “concealment of sexual orientation is known to be related to poorer mental health in sexual minority women”. 

The study authors suggest that worse mental health in bisexual women than in lesbians may be due to more negative social attitudes towards bisexuality compared with lesbian and gay identity. Consequently, bisexual women may have a more negative attitude towards themselves and expect more social rejection, putting their mental health at risk. 

These findings differ from those of a similar UK survey in 2003, which found no difference in psychological distress between bisexual women and lesbians. The authors suggest that legal and social changes in subsequent years (e.g. the 2004 Civil Partnership Act and improvements in public attitudes towards lesbian and gay people) may have benefitted lesbian women more than bisexual women. The 2012 Bisexuality Report highlighted ongoing prejudice against UK bisexual people. 

The authors note their findings may be limited because survey participants were not a random sample of the population and were therefore unlikely to be representative of all UK bisexual women and lesbians. They add that their findings are observed associations and it is therefore not possible to state that bisexual identity causes poorer mental health than lesbian identity.