The effects of out-of-control sexual behaviour can impede relationships and be detrimental to people's views about intimacy, says a leading sex therapist.

After Olympic middle distance runner Nick Willis went public this week about his obsession with pornography and his shame in dealing with it, Sex Therapy New Zealand Central and North Island regional director Mary Hodson outlined what such an addiction involves.

Olympic star Nick Willis on the real victims of his pornography addiction - Women

She said the preferred term for it was "out-of-control sexual behaviour" and there was debate about whether it was something chemically induced in the brain, such as opiate addictions.


Willis has been porn-free for two-and-a-half years and credited his wife, Sierra, for beating his dependence, but Mrs Hodson said many people in his position were too ashamed to tell anyone.

Their behaviour would continue in private and could increase, as they became stressed with bottling up what was happening.

In the internet age, the prevalence of such behaviour was increasing, and would often cause "real issues" in relationships with partners and sexualised perceptions.

Mrs Hodson told the story of one man who used to look at women on the street and think they were "pretty". As his out-of-control behaviour increased, he realised he was now looking at women and imaging having sex with them or what they looked like naked.

"It's interfering with how they live their lives, their relationships and, often, even their work can become quite unmanageable," she said.

"When we're working with someone with out-of-control sexual behaviour we're looking at the kinds of things that may have led them to start the behaviour in the first place and then over-use the behaviour that's becoming detrimental to them.

"It would often start when people were looking to soothe themselves or simply if they were bored.

Sexual therapists would help people displaying such behaviour through "intensive psychological work" including looking at the person's attitude to sexuality.

Addiction Practitioners Association executive director Sue Paton said someone like Willis speaking out would bring the issue to life. "I think people telling their stories is really powerful," she said. "It's powerful for a number of reasons. It helps give people hope, people that are stuck in a cycle."

Ms Paton said addictions can take hold of a person."It's when your life becomes kind of unimaginable, because the focus either on engaging in actively recovering from the activity and planning the next time you're going to engage in the activity becomes all consuming," she said. "The thing with adduction is you feel so hooked with that sense of euphoria."

Addictive activities were pleasurable and some people feel their want for an activity or substance meant they were not in control of themselves. "It's still quite hard to break out of that cycle of getting that reward."

Addictions could also become dependencies, as can be the case with drugs, where somebody felt they needed to take a substance because of negative feelings when it wasn't consumed.

NetSafe executive director Martin Cocker also praised Willis for speaking out.It could let people know help was available and their problems could be worked through.