How love can make us loco: ever notice that a new relationship can cause you to lose all reason? Laura Zigman, author of the novel Animal Husbandry, contemplates why. (On My Mind).(Brief Article)

* You meet a great guy and fall in love. But there's just one little problem: his ex-girlfriend. Only he's not the one who can't stop thinking about her ... you are. In my new novel Her, an otherwise stable woman named Elise becomes so obsessed with her fiance's ex that she starts driving by the ex's house daily. But such scenarios are hardly just fictional. Ex-related insanity--the need to snoop, find nothing, feel reassured, and snoop again--is something I've experienced in almost every relationship I've had.

Sometimes, of course, there have been good reasons to get so deranged by insecurity. There was the divorced man I dated who wore his wedding ring well into the first year of our relationship. And then there was the boyfriend whose ex was so deeply depressed that she sometimes had to "sleep over" at his apartment. But most of the time, just the mere thought that a guy had had a significant other in his past was enough to get me going (even though being involved with anyone over the age of 15 means that he must have some kind of romantic history). Eventually, I realized that fear was at the root of my insanity--fear of being dumped, fear of the unknown, and of course, the mother of them all, fear of losing control.

But ex obsession isn't the only way we become unhinged by our fears. There is also what I call Friend Displacement Disorder, where the earliest stage of a new relationship eclipses almost everything else in our lives--so much so that we begin to lose touch with our closest friends whom we used to speak to six, seven, eight times a day They feel hurt by this abandonment, even though they have done exactly the same thing to us several times.

Or there's Involuntary Projecting, when too early on (like the second date), we begin to have those uncontrollable thoughts: What would our wedding be like? What would we name the ...