Falling in love can act as a potent painkiller, and now scientists have figured out why: It stimulates the brain's reward pathway, much like the rush of an addictive drug.

The next question is whether better understanding of the love-pain relationship might somehow help scientists tackle chronic pain. Falling head over heels isn't exactly something a doctor can prescribe.

But "maybe prescribing a little passion in one's relationship can go a long way toward helping with one's chronic pain — assuming it's passion with the one you're with," said study co-author Dr. Sean Mackey, chief of pain management at Stanford University.