Before the internet was ubiquitous in every aspect of our lives, porn addiction was for the creepy lifelong bachelor or the lonely guy with mommy issues. However, now that we depend on the World Wide Web for much of our information and entertainment, the condition is seeping into parts of the population previously unaffected. Seemingly normal men from all walks of life, including actor David Duchovny and an Australian preacher who faked having cancer to cover up a 16-year porn addiction, are claiming that pornography has taken over their lives.

Is sex addiction a real disease, or just an excuse for behaving badly?  How much is too much?  When does preoccupation cross the line into pathology? The psychotherapy community has been wrestling with such questions for years.

Some addictions are funnier than others. There aren't many good heroin comedies; not even Ben Stiller can wring a laugh out of smoking crack. Alcoholism, on the other hand, has its moments, and by long-standing convention smoking huge quantities of marijuana is truly hilarious. So where in this humor hierarchy shall we put the compulsion to have sex?

Susan Cheever is a novelist, biographer and recovering sex addict. Her new book, “Desire: Where Sex Meets Addiction,” is a cautionary tome about what she calls sex addiction. “Whenever there was a crisis, I found a man to help me take the edge off the feelings of helplessness and pain,” Ms. Cheever writes. "Addiction isn’t about substance — you aren’t addicted to the substance, you are addicted to the alteration of mood that the substance brings. And if that substance is taken away, you’ll replace it with another substance.”

David Duchovny, who currently plays a womanizing writer on the cable television series "Californication," said on Thursday he has entered a facility for treatment of sex addiction.

Sex therapists would argue it is a real addiction with serious consequences. But others in psychiatry and psychotherapy argue it is not comparable to substance addiction and should not be classed as such.

It's my experience that true sex addicts, love addicts, do not have the tools to have healthy, ongoing, ebb and flow relationships.

Experts continually debate whether sexual addiction is a real problem. Some argue that there is no such thing, and that terms like "sexual addiction" and "porn addiction" are unhelpful at best, dangerous at worst.