After Rihanna and Alanis Morissette and Amber Smith and Rachel Uchitel, we've all heard about love addiction--people who feel they can only be happy when they are deep in an all-consuming love. There are a handful of books about it (including Facing Love Addiction by Pia Melody, Women Who Love Too Much by Robin Norwood, Love Addict by Ethlie Ann Vare, and others), and many rehab and recovery centers are now advertising that they help clients with...