Deep Spirits

Intense, passionate feelings of love can provide amazingly effective pain relief, similar to painkillers or such illicit drugs as cocaine, according to a new Stanford University School of Medicine study.

"Love-induced pain relief was associated with the activation of primitive brain structures that control rewarding experiences, such as the nucleus accumbens - shown here in color. Courtesy of Sean Mackey and Jarred Younger"

The concept for the study was sparked several years ago at a neuroscience conference when Aron, an expert in the study of love, met up with Mackey, an expert in the research of pain, and they began talking.

"Art was talking about love," Mackey said. "I was talking about pain. He was talking about the brain systems involved with love. I was talking about the brain systems involved with pain. We realized there was this tremendous overlapping system. We started wondering, 'Is it possible that the two modulate each other?'"

This is very good article and as you said it makes perfecr sense.
Very good example for this is childbirth. Labor is accompanied by intense and prolonged pain, often appearing to be influenced by fear and anxiety levels. Still, as this is life experience connected to love and joy, women repeat it because love and joy overlap pain and anxiety.