Like many women, Rosanne Collins* had her share of one-night stands in graduate school. But instead of outgrowing that risky behavior as she got older, it only escalated as she reached her early 30s. Rosanne started going online and spending hours emailing strangers in Internet chat rooms. "I'd meet people online and engage in sexual intercourse with them at their house," she recalls. "I remember doing that for the first time and thinking, I've got to do this again. Not because it was wonderful, but because it wasn't enough. You're looking for something to make you feel better."

Rosanne thought about sex all the time. In the same way some people daydream about an upcoming vacation, she would spend hours at work thinking about getting home and logging onto her computer ‑- and who she'd meet online. "It's not like a fantasy; for me, it was about the planning and the anticipation," she says. "The sex itself was always bad. There's nothing about it that's satisfying. And yet it's never enough to make you stop. I even remember times when I'd be in the middle of a sexual encounter, and I would be planning the next one in my head. There's such a high that goes along with the pursuit of the next sexual encounter."

Just as alcoholics aren't choosy about what they drink, Rosanne didn't care whether she was attracted to the men she slept with. "It's not about the person," she explains. "You're just looking for something. If you're on the Internet, willing to have sex with someone you've never seen, anything will do. At the same time, you are so disgusted with yourself ‑- you want to physically clean yourself afterward. You can't believe that you'd do this, and yet you start to look for something again."