Was your question asking about what happens "medically" with the withdrawal process - or all the other impacts?
The medical references don't really cover big issues - getting users in to some rehab programme in the first place, and despite stating that meth is (many times) "more addictive" than other drugs, no attempt seems to have been made to explain why that might be. I'm pretty sure that physical withdrawal symptoms from meth addiction are no worse and probably milder than for opiate addiction - and the physical harm from addiction is even worse (and permanent).
What I was actually wondering was how meth users would react if their supply was cut off. Would this create such huge social problems that it would actually be better just to let them have their drug, in which case, is it socially responsible to do a good job of cutting off supply? I don't know. I wondered what others thought about this.
I would say you would have to put them on methadone or something, if you cut everybody off completely I would say all hell would break loose. Think of the billions going back into the economy though that was not being spent of meth.
I don't think there is a "methadone equivalent" for methamphetamine addiction. The articles linked to suggest that some pharmaceuticals may assist with treatment, but methadone is an opiate substitute (for ie heroin), potentially very harmful just like the opiates it's used to wean off dependency, useful because it's long acting (thus reduces craving apparently), taken orally (thus reducing/eliminating the risks associated with uncontrolled intravenous use), works sometimes to wean users off, but IIRC when heroin was a much bigger problem than it is now, addicts had a hell of a battle if they did want to get clean as it was very hard to get access to methadone programmes. Social attitude as a result of the "war on drugs" - these people are "criminals" - so "why should we throw $$$ at solving their self-inflicted misery?". Problem was junkies were responsible for a hell of a lot of petty crime, nobody bothered to include that cost into the equation. They're also still our fellow human beings - they are "us".
If NZ methamphetamine use is about the same as Aus, then NZ market size could be about $2 billion PA. That's all very high profit business for crime syndicates, they pay no tax on the profits, presumably many of their customers rely on welfare and/or crime to get the money to give to the gangsters. Occasionally some get busted and a few gold-plated motorcycles and European cars get seized from the dumbest-end of the methamphetamine retail distribution market (dumb because keeping a low profile is surely a smart move - maybe those idiots didn't watch "Breaking Bad" for some practical tips of the most basic kind - or maybe they're meth users themselves - and that recklessness is just a direct consequence of an effect of the drug). A few million in seized assets is only the tip of an iceberg when you look at the market size.
So I'm told, there are many casual/occasional rather than habitual meth users. I've no idea how usage figures could be broken down between numbers of habitual heavy users and occasional light users - even if total use was able to be accurately estimated. I have no idea why the hell people would even "try it" - it's not as if there's a paucity of information about how harmful it is. OTOH the "war on drugs" has consistently overstated the harmful effects of many recreational drugs, maybe people believe that it's not as harmful as is stated. OTOH (again), seeing kids with paper bags sniffing solvent used to be a common sight, seeing people rolling drunk still is.