To be madly in love might be exactly that–madness. The term “lovesick” is surprisingly accurate, claims a cover story in this month's National Geographic magazine, citing research published over the last several years.
People experiencing romantic love have a chemical profile in their brains similar to that of people with obsessive-compulsive disorder, noted the author, psychologist Lauren Slater. . .
Studies around the world show that passion usually ends. Biologically speaking, the reason romantic love fades may be found in the way our brains respond to the surge and pulse of dopamine. Perhaps the brain adapts to the excessive amounts, and the neurons become desensitized.
Link.
C.S. Lewis pointed out that there is a big difference bewteen "being in love" and "loving" someone. Being in love is a maddening, delirious state. It must end, he said. Otherwise, we'd never get anything done in life. But when it ends, it is supposed to be replaced by love itself. Too many people don't understand this. When the delirious part stops, they think they no longer love the person.
Maybe this dose of science will help them understand this fundamental metaphysical truth. (This is, incidentally, just another instance of science affirming what "unscientific" wise men have known for ages.)