New Zealanders need to have an informed debate about cannabis, distinguishing recreational use from the drug's potential medical application, psychiatrists say.

In the latest issue of the New Zealand Medical Journal, which includes studies on self-reported medicinal use of cannabis and the effect of law changes on synthetic cannabinoid use, an editorial argues for clear public debate.

Part of the problem in discussing cannabis use in New Zealand stems from difficulties obtaining reliable data about an illegal drug and the confusion around use of the term "medical cannabis."

University of Otago psychiatrist Dr Giles Newton-Howes and Capital and Coast District Health Board addiction psychiatrist Sam McBride, in a journal editorial, say objective research is difficult in New Zealand.

Investigating the potential uses of cannabis as a medicine was a sensible approach, although existing evidence was far from conclusive, the authors said.

A parallel approach was needed, focusing on the debate around decriminalising alongside continued investigation of the usage and regulation of...