Experiencing the stress of discrimination and stigma has a direct negative effect on health, reports a study released today in the journal JAMA Internal Medicine. The research examines and compares the health risk factors of lesbian, gay, bisexual, and heterosexual adults in the United States. While all members of these populations have experienced psychological distress and poor health, it is bisexual individuals who appear to be most likely to report impaired physical and mental health.

Researchers from Vanderbilt University and the University of Minnesota compared data from physiological and mental health surveys taken by 525 lesbians, 624 gay, 515 bisexual, and 67,150 heterosexual American adults (Transgender individuals were not included in the study because they are typically not included in federally sponsored health surveys).

It was only in 2013 when the National Health Interview Survey (NHIS) began to include questions about non-heterosexual orientations. For this paper, the researchers drew data from the NHIS physical health survey, which also includes a mental health and substance use measurement. For mental health, participants were asked to self-report how they felt on a Kessler 6-Item Psychological Distress Scale, which asked participants whether in the past 30 days they had felt nervous, hopeless, worthless, and “so sad that nothing could cheer him or her up.”

Study author Gilbert Gonzales tells Inverse that some of the biggest health concerns for LGB adults are higher rates of psychological distress, which can be linked to depression, anxiety, and even mortality. Gonzalez and co-author Julia Przedworski came to their hypothesis (that impaired health may be the result of stressors) by comparing their data alongside a previous body of research on LGBT health.

“Stigma and discrimination against the LGBT population can lead to lower levels of self-esteem and facilitate feelings of shame and rejection,” says Gonzales by email. “Limited access to marriage during the study period may also be an important contributing factor, as research consistently finds married people live longer and healthier lives. Unfortunately, data in the NHIS does not allow us to explore these specific issues and mechanisms.”

Participants of the 2013 Pride Parade in Twin Cities, Minneapolis.

Among men, the researchers found that 16 percent of heterosexual men, 26 percent of gay men, and 40 percent of bisexual men reported moderate or severe psychological distress. When they examined health risks, the researchers also found that bisexual men reported the highest prevalence of heavy drinking at 11 percent, compared with 5.7 percent of heterosexual and 5.1 percent of gay men. Bisexual men were also estimated to be three percent more likely to be heavy smokers than gay and heterosexual men.

When it came to women, 46.4 percent of bisexual women experienced moderate or severe psychological distress. Comparatively, 28.4 percent of lesbians and 22 percent of heterosexual women felt the same. Bisexual women also reported having the heaviest alcohol consumption rates. The only category where bisexual women did not report the most frequent health risks was smoking: Lesbian women were more likely to be heavy smokers out of the three groups.

“LGB adults experience significant health disparities”

“Findings from our study indicate that LGB adults experiences significant health disparities — particularly in mental health and substance use — likely due to the minority stress that LGB adults experience as a result of their exposure to both interpersonal and structural discrimination,” Gonzales and Przedworski say in a statement. “As a first step toward eliminating sexual orientation-based health disparities, it is important for healthcare professionals to be aware and mindful of the increased risk of impaired health, alcohol consumption, and tobacco use among their LGB adult patients.”

Pride in Milan, Italy.

The researchers behind this paper, while the first to examine the issue with large NHIS data sets, are not the first to link the stressors of discrimination and stigma to poor health. Previous studies, like this 2014 paper in Current Directions in Psychological Science, have linked stigma to broader health issues. In this, Columbia University study stigma, which they describe as the “co-occurrence of labeling, stereotyping, separation, status loss, and discrimination in a context in which power is exercised,” the researchers examined individual mental health and sexual orientation data in relation to the LBG protection policies of the states where the data was pulled. They found that the LGB adults living in states that did not legally protect them had a higher prevalence of psychiatric disorders compared to LGB adults who lived in states that did. This was true when it came to physiological health as well. The researchers write:

“LGB individuals who lived in high-structural-stigma communities — operationalized as communities with high levels of anti-gay prejudice — had increased mortality risk compared with those living in low-structural-stigma communities, controlling for individual and community level covariates…Specifically, LGB individuals living in the most prejudiced communities had a shorter life expectancy of 12 years on average compared with those living in the least prejudiced communities.”

Bisexual individuals are thought to be particularly at risk of stigma and discrimination because they are both marginalized by the heterosexual population and seen with a stigma among gay and lesbian adults.

Bisexuality not a “legitimate sexual orientation”?

A 2013 study by the University of Pittsburgh found that in a survey of 1,500 heterosexual and LGB adults, 15 percent didn’t consider bisexuality to be a “legitimate sexual orientation.” Heterosexual men were three times more likely than gay men to not consider bisexuality an actual orientation.

“Bisexual men and women face prejudice, stigma, and discrimination from both heterosexual and homosexual people,” says lead author Mackey Friedman. “This can cause feelings of isolation and marginalization, which prior research has shown leads to higher substance use, depression, and risky sexual behavior. It can also result in lower rates of HIV testing and treatment.”

The researchers behind today’s JAMA study hope that their work will encourage medical professionals to be “sensitive to the needs of sexual minority patients” when screening patients. Openness and acceptance should be something guaranteed to any person at any time — the least health care professionals can do is make sure that that respect is represented at the doctor’s office.