The country's senior drugs researchers are gathering in Auckland today, to nut out the latest in addiction research.

Massey University is hosting the symposium, which includes talks on the impact of recreational drug users on hospital emergency departments, and alcohol policy changes across the world.

Dr Chris Wilkins will present his research on the immediate impact of legal high laws, introduced in 2013.

He's found regular users upped their consumption of synthetic cannabis, and reduced their use of natural cannabis and alcohol.

Dr Wilkins says that poses an interesting question for researchers.

"If we are going to get increased level of legal high use, are we going to get a public health gain by them reducing the use of alcohol and other more harmful substances."

Dr Wilkins adds the presentation will showcase local addiction research in a variety of different areas.

"This presentation's anything from opioids, alcohol, legal highs, new psychoactive substances and gambling."