"MPDV, in particular, has lead to a range of terrible effects, including psychotic states leading to cannibalistic attacks."
Can you cite more than anecdotes to support this? For what it's worth caffeine can also induce psychosis, like any other stimulant (which is what MDPV is).
"Even the strong and broad legalization proposals, in which I can see the wisdom, acknowledge the need to control substances which regularly cause users to behave violently toward persons or property."
I'm not sure you could regulate these drugs in the same manner as alcohol, because they really are significantly worse in terms of both biochemistry and societal harm. (As an aside, certainly alcohol causes far worse damage, but only because it's far more prevalent.)
Let's start with the biochemistry. MDPV is both a norepinephrine-dopamine reuptake inhibitor and a dopamine releaser. For most users, it provides a short and intense cocaine-like high lasting several hours before abating.
However, in a significant minority of users, the dopamine receptors seem to get stuck in the "on" position. The resulting flood overwhelms lower behavioral centers and results in intense hallucinations of danger, psychomotor agitation, and uncontrolled aggression. See http://www.pbs.org/newshour/multimedia/bath-salts/
As to the attacks, here's a few, just from my hometown:
"Scranton police have witnessed several incidents in recent months, however, and found that abuse of the disguised salts leaves a user with feelings of constant and extreme paranoia, imminent danger including threats on their lives, and hallucinations that have kept some hospitalized for up to five days.
In one case, a man in a third story apartment believed to be using bath salts heard a knock on his door, according to Klein. He thought he was under attack, jumped out the window and shattered his ankle.
“Previously, we had a guy that was injecting it at his house (on West Elm Street) in West Side, and he had his elderly mother and father locked in a bathroom,” Duffy said. “We had to have our negotiators come out, and he was actually injecting it as he was coming out of the door to talk to police.”
“Two days ago, a complainant asked officers, ‘Can you see the two males across the street?’” Scranton Police Capt. Carl Graziano said Thursday. “He’s seeing them, and there’s nobody there.”
On Wednesday, March 9, alleged bath salts abuser Ryan Foley, 25, of Scranton, was charged with breaking into St. Ann’s Basilica and stabbing and bludgeoning the Rev. Francis Landry. In a message to parishioners dated March 13, Landry wrote that he suffered “12 stab wounds and lacerations and at least six bruises” in the attack."
I think the main argument is along the lines of "If people could get [amphetamine/cocaine/drug of similar effect but better safety profile] legally and cheaply, they wouldn't be using random shit whose number-one design criteria was sidestepping the Analog Act"
Obviously those other drugs are still harmful, but at least we have the benefit of research into their nature and specific harms.
And DARE classes would probably be a lot more effective if they focused on which were the least bad.
Can you cite more than anecdotes to support this? For what it's worth caffeine can also induce psychosis, like any other stimulant (which is what MDPV is).
"Even the strong and broad legalization proposals, in which I can see the wisdom, acknowledge the need to control substances which regularly cause users to behave violently toward persons or property."
We already have a model for that: alcohol.