Addicted in Hollywood: Fame, Fortune and the Dark Realities of Sexual Addiction

In a case of life imitating art, actor David Duchovny, who plays a sex-addicted writer on the hit Showtime series “Californication,” entered rehab for real-life sex addiction three years ago.

“I have voluntarily entered a facility for the treatment of sex addiction,” Duchovny said in a statement released at the time. “I ask for respect and privacy for my wife and children as we deal with this situation as a family.”

Although wife Tea Leoni stood by his side then, earlier this month the couple announced they were separating for the second time in their 14-year marriage.

But Duchovny is not alone.

Russell Brand’s obsession with sex was once so raging that he hired “a team of experts” to seek out women to fulfill his insatiable need for random sex, before heading to rehab.

In his recent memoir “Stories I Only Tell My Friends,” teen heartthrob Rob Lowe, who entered rehab in 1998 for drug and sex addiction, recalled the scandal that erupted after a videotape of him having sex with two girls (one of them underage) leaked, and admitted at one point he couldn’t go without sex for more than 30 hours.

“AKA” director/writer Duncan Roy turned to Dr. Drew’s “Celebrity Rehab” to treat his obsession with straight men and addiction to Internet porn.

Addicted in Hollywood: Scary Lengths Stars Go to Stay Scary Skinny.

And not all sex addicts are guys.

Former beauty queen Kari Ann Peniche, who became a household name after appearing in a sex tape with Eric Dane and Rebecca Gayheart, entered Dr. Drew’s reality television treatment program to quash her addiction to love and sex. Model Amber Smith sought help for "stalking" men like her father. And author Kerry Cohan even divulged details of her litany of hookups and carnal cravings in the 2008 book “Loose Girl: A Memoir of Promiscuity.”

So what makes someone a a sex addict?

A sex addict has an intense drive and preoccupation with sex, is unable to sustain healthy personal relationships, attempts to justify or blame others for their behavior, and engages in risk-taking – despite the dangerous and negative consequences, they just can’t stop. Sex addiction can also evolve to involve illegal activities, including picking up prostitutes, exhibitionism, peeping and sexual assault.

And experts say Hollywood is a sex addict magnet.

“The Hollywood and celebrity circuit is filled with narcissism. Most people are very self-indulgent and once the thrill of public accolades gets dull, they need to stay in the spotlight,” explained addiction specialist and author of “Younger (Sexier) You,” Dr. Eric Braverman. “Drama kings and queens tend to need attention, which dries up in their brain. By having sex with many people the thrill of still being in the spotlight is met. However, this is not a meaningful thrill; it is very phony and only lasts temporarily, so they need the next partner.”

What’s the difference between an addict and someone who just has a lot of sex?

“Not every man or woman who cheats on their partner is a sex addict, but there is both behavioral evidence and neurochemistry to support the idea that compulsive sexual behavior can be a form of addiction,” CEO of the star-studded Malibu Rehab Facility Promises, Dr. David Sack, told FOX411’s Pop Tarts. “Compulsive sexual behaviors seem to be regulated by the brain chemical dopamine which also governs our reward experience. People that we would call sexual addicts exhibit the same kind of craving, compulsion and withdrawal that we see with addicting drugs.”

The clinical diagnosis of a sex addict is still a controversial one, however. The term is not recognized in the Psychiatric Diagnosis Manual, and last year the American Psychiatric Association announced that their upcoming 2013 manual will include a "behavioral addictions" category that includes gambling, but not sex. So is it possible that copping to so-called sex addiction is simply an excuse for one to justify their philandering?

"Sex addiction is one of those pop psychology diagnoses that has scant scientific support," Scott Lilienfeld, Associate Professor of Psychology at Emory University and co-author of "50 Great Myths of Popular Psychology," told LiveScience. “It's not at all clear whether the term explains, rather than merely describes, people's sexual behaviors. When we hear that someone has a 'diagnosis' of sex addiction, we haven't really learned anything new. We've merely applied a label summarizing what we already knew—basically that the person has serious trouble containing his or her sexual impulses."

Whether it is defined as a clinical addiction or an inability to contain sexual impulses, its consequences can be dire.

“Recently I spoke with a wife who found out her husband was bisexual because of highly promiscuous activities with men. She was coping with it through individual and couples therapy until she found out that her husband was having unprotected sex with gay men,” Sacks said. “He subsequently became HIV positive and she was about to be tested. The betrayal she felt first because he lied to her, then because his behavior became more extreme and finally because he put her health and life in jeopardy was heartbreaking.”

Furthermore, Jaffe said he has treated sex addicts who literally masturbate until they bleed, have had multiple extramarital partners, and despite losing several marriages over it, still find themselves compulsively drawn to online porn and anonymous sex and dating websites.

“Some of the most difficult stories I’ve heard involve individuals who were abused at an early age and have learned to associate that abuse with love/intimacy especially in young children,” Angeles-based addiction specialist Dr. Adi Jaffe said. “That sort of early learning can lead to pretty distorted behavior later in life, and that can then get people locked away for life.”

So how does one spot a sex addict?

“The signs are often difficult for someone from the outside to perceive, especially because of just how taboo sex issues are in society. You’re not going to know if someone is spending eight hours a day masturbating to porn unless you live with them, and addicts are good at hiding it,” Jaffe explained. “Signs start to become obvious when the addiction goes into full-swing, at this point people are losing sleep, missing out on important commitments, and if their sexual acting out involves illegal activities, then they might start getting into legal trouble.”

The Internet, phone technology, and social networking have made sexual compulsion a whole lot easier to act out. According to Sacks, people are now exposed to graphic sexual imagery at a much younger age, and pornography is available at the touch of a keystroke.

“Websites that encourage hookups and cheating have proliferated," Sacks said. "And now geolocator apps that run off of your cell phone GPS signal allow you to find people to hook up near where you are, any time, day or night.”