Tiger Woods and Russell Brand both claim to suffer from it. And there’s a multi-million dollar rehabilitation industry built around it.
But others claim there’s no such thing as “sex addiction”. Unlike drug and alcohol addiction, it’s not included in the Diagnostic and Statistical Manual of Mental Disorders (DSM).
Ken Fergusson says he's a recovering sex addict whose life unravelled due to his uncontrollable sexual behaviour.
"One day I was in contact with someone from Perth. They had just come home so I was chatting to them, telling them that I wanted to see them on the webcam. I was literally begging this woman to take her clothes off and get naked on the bed, basically. She had just been to a funeral, but I didn't care. I just wanted a fix," he told Insight.
"That was the first time that I really noticed that something was not right, when I'm begging them to take their clothes off and have cyber-sex, who has just come back from a funeral, not caring about how they felt."
Ken is now in therapy and trying to save his relationship with partner Gillian.
Gillian says while Ken turns to sex with strangers for lust, he is "sexually anorexic" with her, as he's not able to be intimate and have sex with the same person. She says this was also a sign that Ken needed to get help.
Clinical psychologist Dr David Ley doesn't believe sex addiction exists. “This is a load of malarkey. It is pop psychology gone far astray because people are using it as a label to avoid responsibility”.
Jesse Fink says he had sex with hundreds of women after his marriage breakdown. He agrees sexual addiction is just an excuse for bad behaviour.
"I just think it's a crock of shit. It has lost its meaning - people who are caught out doing terrible things throwing the term sex addiction in the air for why they did it. They are not taking responsibility for their decision making".
But sex therapist John Larkin says it is a real condition that can ruin lives.
"It's not about semantics for me. What I see are people who cannot stop, and want to stop certain behaviours, because it's hurting themselves and other people".