September 27 is National Gay Men’s HIV Awareness Day.

We’d been messing around since I was about 10 years old. I figured sex with him and his three younger brothers next door was just a part of our friendship, along with our hikes to Bluff Point, on Long Island Sound, and neighborhood kickball, baseball, football, and foursquare games.

Besides, I enjoyed it a lot. I never felt consciously traumatized.

It would take a 2005 HIV diagnosis to open my mind to how my experience of childhood sexual abuse, and the multiple traumas I experienced throughout my life, undermined my self-esteem and good judgment and put me in the way of the same lethal microbe that killed so many of my friends.

The American Academy of Experts in Traumatic Stress (AAETS) says that 30 percent of all male children are molested in some way. There is a well-documented correlation between sexual abuse and later promiscuity. PTSD, depression, poor self-esteem, dissociative disorders, and anxiety are among the other effects of CSA. Sexual abuse survivors often equate sexual desirability with self-worth—and use sex as an analgesic to blunt the edge of shame that is another insidious effect of CSA.

I know these things, not only from reading about them in the research literature, but because they have played out in my own life—and in the lives of so many gay men.

Behavioral scientists have wrung their hands for more than three decades trying to understand why gay men seem so disproportionately vulnerable to HIV. Recent research makes it abundantly clear that trauma, specifically from CSA, is almost certainly the long-overlooked answer.

Consider: Harvard researchers have found that up to 46 percent of gay and bisexual men who report condomless anal sex—the principal act by which HIV is transmitted between men—were sexually abused as boys.

“That is a huge number,” said Conall O’Cleirigh, a staff clinical psychologist in the psychiatry department at Massachusetts General Hospital and an assistant professor of psychiatry at Harvard. His research on gay men has found that the same mental health issues that can put someone at risk for HIV can also prevent someone living with the virus from adhering to his treatment.

In a national study of 1,552 black gay and bisexual men, O’Cleirigh and his colleagues found that men who experienced CSA—or physical or emotional abuse, or stalking, or being pressured or forced to have sex—when they were younger than 12 years old had more than three male partners in the past six months. The men who had been forced or pressured to have sex as boys were likely to have receptive anal sex.

In another study of 162 men with CSA histories, participants reporting sexual abuse by family members were 2.6 times more likely to abuse alcohol, twice as likely to have a substance use disorder, and 2.7 times more likely to report a sexually transmitted infection in the past year. Not only that, but men whose abuser penetrated them were more likely to have PTSD, recent HIV sexual risk behavior, and a greater number of casual sexual partners. Physical injury and intense fear increased the odds for PTSD even more.

“Having that history is repeatedly associated in every sample of gay men with increased likelihood of being HIV-positive,” said O’Cleirigh. He said that since CSA is “very, very common in gay and bisexual men” it appears to be one of the most significant vulnerabilities that accounts for the disproportionately high rate of HIV among gay men.

Prevention educators long have wanted to believe that handing out condoms, or, more recently, the HIV medication Truvada used as pre-exposure prophylaxis to prevent HIV infection, should suffice for men at the highest risk who engage in unprotected anal sex with partners of unknown HIV status. But increasing rates of new HIV infection among gay men—the only U.S. population with increasing, rather than declining, rates—are proof that condoms and PrEP alone aren’t enough.

The only way to arrest the spread of HIV among gay men is to address the trauma that undermines their self-esteem and good judgment.

An effective risk-reduction/health-promotion intervention that addresses the effects of childhood sexual abuse could help make gay male survivors more conscious of what they are doing and where it’s coming from in their psyche. It could also finally reduce the “hardcore” of gay men beyond the reach of more traditional prevention efforts.

At Boston’s Fenway Health, O’Cleirigh helped recruit the nearly 5,000 gay and bisexual men who participated in Project Thrive, an intervention aimed at helping gay men who experienced CSA to increase their coping skills and ability to be more present in—rather than dissociating from (a common effect of CSA)—their immediate situation, and provide specific skills to evaluate and reassess these situations.

“Treatments [counseling and therapy] are geared toward giving the men a more realistic sense of the world,” said O’Cleirigh, which is an important ingredient of resilience. “As we say to our clients, we can’t change the fact that you were abused, but you can change.”

Healed gay men protect themselves and their partners, and take their meds if they are positive.

The message for this National Gay Men’s HIV-AIDS Awareness Day should be that helping gay survivors of childhood sexual abuse to heal from trauma can profoundly reshape the way they think and make choices about sex—and about their health.

This is how new HIV infections among the “hardcore” will stop, and the surest way for those of us living with the virus to stay healthy.

John-Manuel Andriote is a Connecticut-based writer.