Drug dependent Hunter Valley residents will be part of a world first study into a cannabis withdrawal management drug.

Dozens of people are needed for the study involving a trial site at Belmont Hospital.

They will be given the drug Sativex via a mouth spray to see if it helps them to manage their withdrawal symptoms.

The Director of the National Cannabis Prevention and Information Centre Professor Jan Copeland says participants will be hospitalised free of charge.

"We need 50 participants," she said.

"It's an in patient study so people need to be able to commit to 7 or 8 days in an in patient situation."

Professor Copeland says the study will have ramifications around the world.

"It will be a complete game changer for the treatment of cannabis dependence," she said.

"So it is very important that we get this first study right and then we move on to community based studies.

"We are also testing safety aspects in this particular study, driving skills and things like that."