WELLINGTON, New Zealand (AFP) — Sex addicts feel threatened by intimacy and are more insecure about romantic relationships than the rest of the population, a New Zealand study has found.

The survey of more than 600 people found those who indulged in compulsive sexual behaviour felt anxious and insecure about relationships and tried to avoid becoming too emotionally attached to others.

Massey University said the study, conducted by psychology honours student Karen Faislander under the supervision of a practising clinical psychologist and an academic specialist, was the first of its type in New Zealand.

Faislander said sex addiction, which made headlines this year with revelations about Tiger Woods' love life, was a complex condition that had not been researched as thoroughly as areas such as substance abuse or depression.

She said the term "sex addict" first emerged in the early 1980s and there were 29 other terms in scientific literature that described the condition, including sexual compulsivity, excessive sexual desire disorder and hypersexuality.

The preferred contemporary term is out-of-control sexual behaviours (OOSCH).

"It's widely misunderstood and stigmatised," Faislander told AFP.

"There's no known effective treatment. We don't know what causes it or how we treat it."

Because of the embarrassment people feel discussing the subject, Faislander's study used an anonymous online survey to quiz 621 people about their sex lives. 407 identified themselves as sex addicts while 214 were not.

The survey asked if they engaged in online sex, prostitution, sex in public or with multiple partners, as well as examining areas such as alcohol use and feelings of self worth.

"The OOCSB group reported higher rates of insecure styles of attachment, characterised by a perspective of relationships as threatening, and feelings of either anxiety towards or avoidance of closeness or intimacy," the study found.

In contrast, non-sex addicts found intimacy desirable and rewarding, felt secure in relationships and regarded their partners as trustworthy.

Faislander said studies estimated three to six per cent of the population had the condition in the US, where sex addiction clinics have sprung up in recent years treating stars such as Woods, actor David Duchovny and comedian Russell Brand.

She said no such treatment was available in New Zealand, where self-help groups including Sex and Love Addicts and Sexaholics Anonymous use 12-step programmes based on those pioneered by Alcoholics Anonymous.

While Faislander's study was not peer reviewed, she hopes to gain a doctorate in clinical psychology and conduct further research on treating out-of-control sexual behaviours.