As everyone knows, sex feels good.

Or does it? In recent years, I’ve come across several patients for whom sex is not just unpleasurable; it actually seems to cause harm.

One patient, a young man in his mid-20s, described it this way: “After sex, I feel literally achy and depressed for about a day.”

Believe me, I could have cooked up an explanation very easily. He had hidden conflicts about sex, or he had ambivalent feelings about his partner. Who doesn’t?

Could it be that some patients have particularly strong rebound activity in the amygdala after orgasm that makes them feel bad?

A clue to a possible treatment is that Prozac and its cousins, selective serotonin reuptake inhibitors, commonly interfere with sexual functioning to some degree. Serotonin is good for your mood, but too much of it in your brain and spinal cord is decidedly bad for sex.