Addiction is the hallmark of every infatuation-based love story. It all begins when the object of your adoration bestows upon you a heady, hallucinogenic dose of something you never even dared to admit that you wanted—an emotional speedball, perhaps, of thunderous love and roiling excitement. Soon you start craving that intense attention, with the hungry obsession of any junkie. When the drug is withheld, you promptly turn sick, crazy and depleted (not to mention resentful of the dealer who encouraged this addiction in the first place but who now refuses to pony up the good stuff anymore—despite...