Research has found that lesbian, gay, and bisexual Americans suffer from several health disparities compared to their heterosexual counterparts. For example, LGB adolescents and adults are at increased risk for several mental health issues, including depression and suicide. These disparities also extend to their physical health: Not only are LGB adults more likely to be in poor overall health, but they also have a heightened risk of developing cancer, cardiovascular disease, diabetes, and numerous other chronic health conditions.

So why is that? The most popular—and well-supported—explanation to date is known as the minority stress model. The idea behind it is simple: LGB people have frequent experiences with prejudice and discrimination that are stressful, and all of this stress eventually takes a toll on their health.

A new study published in the journal Psychology of Sexual Orientation and Gender Diversity adds an interesting new angle to minority stress theory. This research suggests that the health disparities affecting lesbian, gay, and bisexual adults aren’t just a direct function of stigma-induced stress—rather, this stress may indirectly affect health by interfering with sexual minorities’ ability to get a good night’s sleep.

Scientists have increasingly found that sleep is vital for maintaining good physical and psychological health. Sleep problems have been linked to everything from depression and anxiety to sexual difficulties to high blood pressure and diabetes. How much sleep do you need to maintain good health? For adults between the ages of 18 and 64, the recommendation is seven to nine hours per night.

Given the powerful link between sleep and well being, it stands to reason that if LGB adults are having more sleep problems, this might explain—at least in part—many of the health disparities they are experiencing.

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So are LGB adults indeed getting less sleep? In order to answer this question, researchers analyzed data from a large, nationally representative survey of Americans that included more than 15,000 participants. Participants were 29 years old on average and most (96.6 percent) identified as heterosexual, with 2.1 percent identifying as gay and 1.3 percent as bisexual.

Included in the survey were two questions about insomnia, which focused on problems falling asleep and staying asleep. Participants also answered questions about the amount of stress they were under in the last month and the quality of their relationship with their parents. Relationships with parents were a major focus of this investigation because parents are one of the biggest sources of emotional support in most people’s lives. The authors argued that strained parental relationships were likely to be a major source of stress for sexual minorities, who all too often find themselves kicked out of their homes or rejected by their families.

What the researchers found was that, compared to heterosexuals, LGB adults were more likely to report problems both falling asleep and staying asleep. Incidentally, in addition to this sexual orientation difference, there was also a gender difference: Regardless of sexual identity, women reported more issues with insomnia than men, a finding that replicates a lot of previous studies on sleep difficulties.

Also, relative to heterosexuals, LGB participants reported having lower quality relationships with their mothers, but especially with their fathers. LGB adults reported experiencing higher levels of stress in the last month, too. The key analysis in this study involved testing an elaborate statistical model, which found that identifying as LGB predicted having lower quality relationships with one’s parents. This, in turn, predicted experiencing more stress—and this stress ultimately predicted more sleep difficulties.

In other words, the overall model suggests that when LGB persons are socially rejected by their families, it creates stress and, further, the more of this stress they experience, the more likely they are to develop symptoms of insomnia.

Transgender people weren’t specifically included in this study, so the results don’t necessarily speak to them. However, it is important to address sleep issues in trans persons in future research, given that—like LGB people—they often experience a lot of stress and social rejection due to their minority identity.

Although the researchers didn’t specifically look at health problems in this study, the implications of sleep deficits have already been well established. As a result, the sleep disturbances documented here should now be seen as a prime candidate for explaining some of the mental and physical health disparities affecting the LGB community.

The implications of this are big because, in recent years, a lot of research attention has been devoted to ways of reducing sexual minority health disparities. To the extent that sleep disturbances are one of the big contributors, treatments focused on improving sleep could be one important avenue to pursue going forward, especially given that insomnia is often highly responsive to treatment.