The National Institutes of Health is spending nearly $1 million on a study of lesbian couples to see if stress makes them drink too much.

The grant awarded to Old Dominion University will involve lesbians filling out daily diaries about their romantic relationships to determine what causes them to drink.

"Sexual minority women (i.e., women who self-identify as lesbian and bisexual) report more heavy drinking, more alcohol-related problems, and higher rates of alcohol use disorders as compared to heterosexual women," according to the grant for the study. "Young sexual minority women are particularly vulnerable."

The researchers contend that no one has ever studied the relationships of lesbian couples and their drinking habits.

"Despite this awareness, no studies have examined how relationship factors and partners' alcohol use contribute to hazardous drinking among female sexual minority couples," the grant said.

The research will be grounded in "Minority Stress Theory," which blames discrimination and stigma for "negative mental health outcomes." The latest grant, awarded this year, is a follow up to previous work that found "minority stress is associated with alcohol use and related problems via negative affect among lesbians."

"Extending our previous research, we propose to examine how person-level factors and daily interactions contribute to drinking among female same-sex couples," the grant said.

The project will employ a "daily diary approach" where lesbians will discuss their alcohol consumption, relationship experiences, and "person-level factors," such as "connection to the LGBT community" and "positive sexual identity."

One hundred fifty lesbians will be recruited for the study online.

"The present research will contribute to our understanding of the mechanisms by which sexual minority women's romantic relationships and experiences of minority stress contribute to alcohol use," the grant said. "In turn, this information can inform efforts to reduce sexual minority women's health disparities and improve their health and well-being."

The study has cost taxpayers $911,056 so far and will continue through July 2019.

Researchers said the project is important because "young adult sexual minority women are at greater risk for problematic alcohol use than heterosexual women."

"The proposed research examines how alcohol use is associated with relationship factors, sexual minority stress, and negative affect in young adult female same-sex couples," the grant said. "Increased understanding of the factors contributing to problem drinking will facilitate progress toward reducing health disparities and improving health in this underserved, at-risk population."