With the news yesterday of the attempted arson of a legal highs store in Invercargill, it's reasonable to ask whether we're on the verge of public hysteria about synthetic cannabis. The next question would be why it's happening now, when 95% of retail outlets for such products have been either shut down or forbidden to to sell the products -- and those remaining are closely monitored and, for the first time, required to be strictly R18 premises.

The Psychoactive Substances Regulatory Authority, which administers the fledgling regime established under the Psychoactive Substances Act, has also not been shy about banning products deemed unsafe under its assessment guidelines. The entire JWH group of synthetic cannabinoids, which provided the psychoactive ingredients of most of the products that, before the Act, could be sold to kids from corner dairies, is now gone.

The list of products deemed low-risk and granted interim approval is a fraction of the nearly 300 legal highs sold in the past few years, before the new Act. It includes half a dozen fairly harmless pill products containing caffeine, guarana, kava, green tea and amino acids, and the rest is synthetic pot. When the full approval process gets underway, all of these will be banned subject to the Authority being satisfied that they present a low risk. It is quite possible that no products administered by smoking will meet the standard.

So, why now? Why now, when the prevalence of acute cases is reportedly beginning to fall? My guess is that we're reaping the harm of the years when the goverment was playing whack-a-mole, banning one substance after another without attempting to deal with the problem in the whole through regulation.

That certainly seems to be the case with 17 year-old Jesse Murray, whose tragic story has unfolded in the past week in The Press and other Fairfax papers. He and his mother say he has been smoking synthetic cannabis since he was 14 and he is now clearly addicted. But here's the thing I just can't process about that story:

His days are dictated by the opening and closing hours of the nearest legal high shop. If he has the money, he will hand over anything between $25 and $80 a day - money he has begged for. Despite it being illegal for him to purchase the drug because of his age, sometimes, out of sympathy, the storekeepers give it to him for free.

Let's be very clear here: whether they are selling Jesse synthetic pot or giving it to him for free, these storekeepers are breaking the law. The police should be informed and the owners' licence to trade revoked forthwith. Why on earth has The Press published three stories about Jesse but not identified the shops supplying him? Why is The Press sheltering criminals?

I'm not sure by what mechanism the currently available products might be directly causing the stomach bleeding reported by Jesse, but the Authority has already banned products found to be associated with "nausea and vomiting, insomnia, acute psychotic reaction, and prolonged withdrawal". If there are still products on sale that cause such harm, they need to be reported.

It's possible that the real damage was done to Jesse before the new regime, but that doesn't help with his withdrawal problems. Most people use these products without significant problems, but it does appear that some of them more than others cause addiction and other problems. The Wikipedia article on synthetic cannabis notes that the synthetic cannabinoids are full agonists to the cannabinoid receptors in the brain, by contrast with THC, the chief active ingredient in marijuana, which is only a partial agonist -- and the belief that this is the key to severe adverse effects, including toxicity. The absence of cannibdiol (CBD), another cannabinoid found in marijuana, which has demonstrated anti-psychotic effects, may also be a factor.

You might think in light of that, that we're regulating the wrong thing -- that cannabis itself should be subject to the same strict regulation in the place of these new substances. You may well be right, and you might be surprised to find how many MPs are thinking the same thing, but the politics are such that it simply was not possible to apply the new Act to any drug currently illegal under the Misuse of Drugs Act.

I do think that will happen, and that it might not be that long coming, but it won't be until after the Psychoactive Substances Act is fully up and running and has proved its fitness.

Meanwhile, in the illicit sector, we're seeing the same problems that prompted the pasage of the Act. LSD has been made too difficult to manufacture or supply -- so its place in the market has been taken by the NBOMe class of drugs, which are being sold in New Zealand as "liquid LSD". Users don't know what they're getting and, more importantly, how much. The NBOMe drugs have a scary dose-response curve, doses are almost microscopic and some toxic overdoses are being recorded. This keeps happening. That's why we're trying a different approach.

We're at an awkward stage with a legislative approach that is being watched around the world. This is something worth doing. And I hope that the news media can take a balanced approach to what's happening, and that local authorities do what is required of them under the law. Because failure would take us right back to square one.