As a doctor, I can probe, culture, prescribe antibiotics, and aggressively treat and track contagious STDs. But depression is different. It’s more elusive, yet equally, if not more, dangerous. It can come and go, or it can settle in, making itself so comfortable in an adolescent’s psyche that it’s nearly impossible to extricate. There, just as many STDs do, depression causes permanent damage that may not become apparent for years. To many teenagers, depression can make them feel as though another entity has moved into their body, taking over everything they think, feel, and do.

For the thousands of teens I’ve treated and counseled, one of the major causes of depression is sex. I consider it an STD with effects as devastating as—if not more—HPV, chlymadia or any other.

Just ask any doctor, therapist, or teacher who works closely with teenagers and they’ll tell you: Teenage sexual activity routinely leads to emotional turmoil and psychological distress. Beginning in the 1970s, when the sexual revolution unleashed previously unheard-of sexual freedoms on college campuses across the country, physicians began seeing the results of this “freedom.” This new permissiveness, they said, often led to empty relationships, to feelings of self-contempt and worthlessness. All, of…