MedicineNet.com lists several behaviors that could be considered part of sex addiction. Some include: compulsive masturbation, multiple affairs (extra-marital affairs), multiple or anonymous sexual partners and/or one-night stands, consistent use of pornography, unsafe sex, phone or computer sex, prostitution or using prostitutes, exhibitionism, and obsessive dating through personal ads.

SM: What about characters like Samantha on Sex and the City, she just seems to like sex, but could she be considered an addict?
Pinsky: Samantha absolutely was a sex addict, categorically. In fact, I know a woman who lived with that person who the character was fashioned after, and she became a prostitute and died of cocaine addiction. I was so angry about Sex and the City, because [of] all three of those women, the [Cynthia] Nixon character was the only one that wasn’t sick. The other three were desperately, mentally ill. It was not portrayed or thought of that way when in fact that’s what it was.

SM: Why would Samantha’s behavior be a problem?
Pinsky: Addiction is a fatal disease. Whether it is sex addiction or cocaine addiction or heroin addiction, it is a progressive illness and the consequences get worse with time. It may be a slow progression and it may not progress to fatality. But it always progresses towards fatal. For instance, we look at Paris Hilton and Lindsay Lohan and Nicole Richie and people are like ‘oh boy, such childish behavior.’ No, two of those women will be dead within the next five years. We’ve already lost Anna Nicole [Smith] to the same disease.