The founder of the Bergen four-day treatment for Obsessive Compulsive Disorder (OCD) says the intensive process achieves better results than more drawn-out treatments.

The method has had promising outcomes overseas and is now being trialled here by a group of 17 New Zealanders aged 18- to 25-years-old.

Dr Bjarne Hansen told RNZ the condition was characterised by intrusive thoughts of dangers or bad things happening that sufferers must attempt to control.

"You're afraid of your own thoughts and end up in endless efforts to try to control your thoughts and keep people safe," Hansen said.

Hansen said four-year follow-ups with patients who had used the treatment overseas had shown up to 70 percent moving on with no significant symptoms.

He said treating people with the mental disorder when they were young reduced the prolonged impact of the condition on sufferers as well as health systems.

"It's highly stable and people would most often suffer this 10, 20, 30 years later - if they don't get the right kind of treatment - so it makes sense to start with young people," Hansen said.

It's hoped the process could be a game-changer for the nearly 100,000 New Zealanders who suffer from OCD.

Hansen said focusing the treatment over a continuous four-day program allowed patients a better opportunity to disrupt the disorder.

"If you have 45 minutes once a week - even for years - you will not have enough time to really recognise and break this pattern so having full four days is actually giving you more time to recognise, to change and get the support you need to change this pattern," Hansen said.

Hansen said he was buoyed by the support of medical research charity Open Closed Doors and the interest shown in the treatment in New Zealand.

"We have had so many excellent collaborators in New Zealand. Yesterday we had a full day of training here and the opposition spokesperson for mental health, Ingrid Leary did participate the full day - being so interested and supportive of this work.

"So I really think that - with the people you have here - all the patients, the professionals, politicians being involved I think [New Zealand] can really make this happen and make this available to more people," Hansen said.

Co-founder of Open Closed Doors, Megan Jones said her organisation had been looking at different ways to treat OCD.

She said five experts had travelled to New Zealand to train clinicians here while another five psychologists had also travelled to Singapore to train in the process.

"At present, many people living with this condition are struggling to get any treatment at all and the average wait time for diagnosis here is about seven years. This is going to make a huge impact," Jones said.