Such a sad story. But if weed was legal, things like this would be far less likely to happen. Fact. Prohibition is the reason why so many people turn to these legal highs in the first place, not realising that these substances contain all sorts of toxic shit. I've no doubt that she purchased the synthetic weed as an alternative to breaking the law, a law which shouldn't even exist.
The argument that Marijuana use leads to mental disorders is kind of weak. It's been shown in studies that most people who have developed such disorders, had a predisposition for mental illness, it has very little to do with the drug itself. Like many people have said in the Drugs thread, the reason why Marijuana is prohibited is completely down to politics and money. The timber companies, tobacco, alcohol and pharmaceutical giants will not let the government go ahead with legalisation, because they know that legal Marijuana trade will cut into their profits. That's without mentioning the problem of the right wing, fire and brimstone types that hold considerable power over the people that make the tough decisions, especially in the US.
Here in the UK, the idea of legalisation has been discussed, but only tentatively, and as long as we have media outlets like the Daily Mail, and the Murdoch owned Sky News, to scare people into rejecting the idea of lifting prohibition, it won't happen.
Synthetic weed is bad. I've tried it a couple of times, and it's nothing like the real thing. The last time I tried it, I was pretty ill for a couple of days. The thing is, it's so easily available. You can buy it online and have it delivered to your door, along with other synthetic 'drugs' that have also been known to kill people.