Two research studies on suicide are confirming just how tough it is to be young and LGBTQ.

Teens hiding their sexual orientation are at a significantly higher risk for suicidal behaviors, an American-based study reports, and college freshmen in a sexual minority are at top risk for suicidal thoughts, an study of international data says.

In the U.S. study, in the American Journal of Preventative Medicine, investigators warn that teens who hide their true sexual orientation — what researchers call sexual-orientation discordance — have a significantly elevated risk for suicide.

The international study, reported in the Journal of the American Academy of Child and Adolescent Psychiatry, says that nearly a third of first-year college freshman have thought about suicide, and, of those who do, LGBTQ students had a risk that was four-to-eight times higher.

Related: A trans teen left the most heartbreaking suicide note. Her name was Hope.

Even worse, sexual orientation raised the likelihood of moving from suicidal thinking to plans or attempts — by three fold.

Among the students in the international study, heterosexuals with experience of same-sex intercourse were at a three-to-four-fold higher risk. Heterosexuals with same-sex attraction had about double the risk.

The most-recent ranking, from 2015, lists suicide as the second-leading cause of death among American 15-to-19-year-olds, according to reporting by the Centers for Disease Control and Prevention. For 2015, suicide is also the second-leading cause of death among 15- to 29-year-olds internationally, the World Health Organization reports.

At the high-school level, the American-based study comes from a 99-question study of 7,000 U.S. high-school students. It had two questions sexual orientation, and 4 percent of overall respondents said they had experienced sexual-orientation discordance (hiding their sexual identities). Of them, 32 percent were LGBTQ, compared to 3 percent of heterosexual students.

Dig deeper, and the results are just as ominous.

Nearly half of the students who had experienced discordance — 46 percent — reported suicidal behaviors or thoughts, compared to 22 percent of who students who didn’t feel a mismatch between sexual identities and actions.

Non-fatal suicidal behaviors were more common in females, in those who were bullied on school property, in those who drank alcohol and used marijuana, and in those who had been physically forced to have sexual intercourse, the American study reported.

The study’s authors noted their results corresponded with similar patterns in studies of adults.

“Discrimination, stigma, prejudice, rejection and societal norms may put pressure on sexual minorities to present a sexual identity inconsistent with their true sexual identity or to act in a manner inconsistent with their sexual identity,” they said.

Co-author Dr. Francis Annor, of the CDC, said understanding the challenges teens face will help strengthen overall suicide prevention.

“It’s important to know that suicide is preventable,” she said to Reuters.

The international study, on college freshmen, analyzed data from the WHO’s World Mental Health Surveys International Student Project. Data came from eight countries, including the United States, with almost 14,000 responses from 12 public institutions.

Lead researcher Philippe Mortier, a neuroscience researcher at Leuven University, in Belgium, stressed that most students who struggle with sexual-orientation issues will not develop serious suicidality. But, he said, the results show the need for specific research on these high-risk groups.

The international study’s results are an important signal for college administrators, Victor Schwartz, the chief medical officer of the JED Foundation, in New York, told Reuters. JED focuses on emotional health and suicide prevention for teens and young adults.

“Maybe this study will get the attention of a university administrator who will see the suicide problem as not just at their school, but widespread, and it may elevate their level of awareness,” he said.

Ironically, though, while colleges have increased funding for suicide prevention, many American colleges are not tracking deaths by suicide, the Associated Press reported on Jan. 2.

Of the 100 largest public universities contacted by the AP, only 46 of them currently track suicides.

When suicides are reported, schools fear for their reputations, the AP reported. “No school wants to be known as a school with multiple suicides. It’s not good for business,” Nancy Roy, chief clinical officer for JED, told the AP.

Responding to the American research was Dr. John Blosnich, of West Virginia University. He wasn’t involved in the research, Reuters reports, but he studies interpersonal and self-directed violence among LGBTQ groups and U.S. military veterans.

He noted the timing of the just-released movie Love, Simon, which focuses on these issues.

“You can imagine that a huge concern for teenagers who experience conflict with their sexual identity is whether they will be rejected by their family and friends,” Blosnich said to Reuters.