In the first study of its kind in Australia, University of Sydney researchers say they have uncovered the severe impact of porn addiction on users and their families.

But the researchers, Professor Raj Sitharthan of the University of Sydney's Department of Psychiatry and Dr Gomathi Sitharthan from the Faculty of Health Sciences, added that the addiction could be "unlearned" through changing one's behaviour.

The study, which was carried out through internet surveys and was not funded by any organisation, found that about 20 per cent of the 800 participants "preferred the excitement of watching porn to being sexually intimate with their partner'.

It also found that:

*About 43 per cent of participants said they started viewing porn when they were between 11 to 13 years old