Is legalising cannabis a good
or a bad move?
That was the question underlying the presentation by Dr Karen Oldfield, of the Medical Research Institute of New Zealand to an absorbed audience at the club this week.
Dr Oldfield, who is a medical doctor now studying for her PhD focussing on medicinal cannabis is a Senior Research Fellow at the Institute.
She reviewed the state of knowledge about the claimed benefits and downsides of using cannabis and concluded that the evidence for both sides was mixed and inconclusive, despite the claims by both sides in the legalise cannabis debate.
She noted that cannabis had been used a medicine for at least 10 000 years and was also used for religious and recreational purposes.
Dr Oldfield drew a clear distinction between the two active ingredients of cannabis: THC which gives the user the euphoria high associated with getting stoned; and CBD which is said to have therapeutic effects such as relieving stress, pain and anxiety.
CBD is used in Sativex, the only medical cannabis product currently licensed for use in New Zealand, under the Medical Marijuana regime which came into effect in April this year.
The new regime allows GPs to prescribe medical marijuana and thereby frees up access to the drug for those who would benefit from it. Access is still controlled but is now easier to get than under the previous regime where would be users also required approval from the Ministry of Health.
Recreational marijuana is mostly THC, but does contain some CBD, and can be smoked or eaten – in cakes and cookies for example.
Critically for the debate leading up to the referendum later this year, Dr Oldfield said genuine scientific research, as opposed to anecdotal evidence, was inconclusive about both the benefits and dangers of cannabis use.
She cited a large and authoritative 2017 study from the National Academies of Sciences, Engineering, and Medicine in the United States which reviewed the health effects of cannabis and cannabinoids to support her conclusion.