For some, it may just be an excuse to be lascivious, but sex addiction has become an epidemic in the U.S., with over nine million Americans classified as sex addicts.

The phrase sex addict has been taboo in the common society we live in, reserved for the high-profile Charlie Sheen's and the Dominique Strauss-Kahn's out there. How can we forget how Sheen got his nickname Charlie the Machine or how Tiger Woods presumably was treated for the addiction following the split from his wife? But what about the average American, can they suffer from sex addiction?

In a feature story for Newsweek, experts from the Society for the Advancement of Sexual Health said compulsive sexual behavior, or hypersexual disorder, not only exists outside of the Hollywood commune but can affect anyone just as addictions to drugs and alcohol do. In fact, the disorder affects anywhere between three and five percent of the U.S. population, or what Steven Luff, co-author of Pure Eyes: A Man's Guide to Sexual Integrity calls an epidemic.

In response to this epidemic, there have been a growing number of sex therapists, which now exceed over 1,500 compared to less than 100 practicing at the turn of the millennium. Not to mention the dozens of treatment centers for sex addicts.

The addiction has not only spread throughout the population, but into different demographics, as well. It used to be skewed towards men from 40-to-50-years-old, since 90 percent of identifying addicts are male, but now includes a growing population of women and young people.

Where it used to be 40- to 50-year-old men seeking treatment, now there are more females, adolescents, and senior citizens, Tami VerHelst, vice president of the International Institute for Trauma and Addiction Professionals, told Newsweek. Grandfathers getting caught with porn on their computers by grandkids, and grandkids sexting at 12.

Human sexuality has been around since prehistoric times, evolving throughout the years and within cultures, but how did this epidemic exactly become an epidemic?

The answer: porn. Porn and how readily available it is, according to Newsweek.

In the digital world we live in, porn has become easily accessible at any time, place and often times, free of cost. This overdose of virtual sex, including watching porn, sexting, etc., has led to the increase of people wanting more of the real thing. Newsweek reported nearly 40 million Americans log onto the 4.2 million pornographic Web sites in existence...each day.

This almost cannibalistic desire has also been complimented by the media, with shows like Bad Sex coming to prime time television and celebrities like Woods and Strauss-Kahn clogging the headlines with reports about scandals.

Others, however, do not believe the condition exists, let alone be considered an epidemic, despite these figures. Clinical psychologist David Ley, author of an upcoming book The Myth of Sex Addiction, said it's just that, a myth.

The sex-addiction concept is a belief system, not a diagnosis; it's not a medically supported concept, Ley told Salon in response to the Newsweek article which stirred discussion on the topic. The science is abysmal. The thing that drives me craziest is that over the past year or two, [proponents of the sex addiction model] have started trying to use brain science to explain it. They're now talking about morphological changes that supposedly happen in the brain as somebody watches porn or has too much sex.

According to Robert Weiss, founder of the Sexual Recovery Institute in Los Angeles, sex addiction is just like every other addiction, causing a dependency on the dopamine one gets from partaking.

It's all about chasing that emotional high: losing yourself in image after image, prostitute after prostitute, affair after affair, Weiss told Newsweek They end up losing relationships, getting diseases, and losing jobs.

Experts and therapists hope the probe into the sex addiction epidemic will stimulate awareness and a cure for the disorder, but, based on reactions from other experts, it looks like they will have to do some more convincing first.