Bath Salts More Addictive Than Meth In Rats
July 10, 2013

Researchers Say Bath Salts Are More Addictive Than Methamphetamine

Brett Smith for - Your Universe Online

Although they may have been disproven as a source of the coming zombie apocalypse, bath salts are still very much a public threat. A new study from scientists at The Scripps Research Institute in La Jolla, California has found that the designer drugs are more addictive than methamphetamine.

The active ingredient in bath salts, MDPV, is a powerful stimulant derived from the main active ingredient in khat, a leaf chewed for its stimulant effects by people across northeast Africa and the Arabian Peninsula.

"We observed that rats will press a lever more often to get a single infusion of MDPV than they will for meth, across a fairly wide dose range," said Michael A. Taffe, a Scripps neurobiology scientist and co-author of the study that appeared in the journal Neuropharmacology.

When anecdotal reports of the drug began circulating through the media, Taffe and his Scripps colleague, Tobin J. Dickerson, began working on studies with laboratory animals.

"The drugs had not yet been scheduled, and we were able to work out how to synthesize them in sufficient quantities for animal testing," said Dickerson, a chemistry professor at Scripps.

The researchers began by comparing the effect of MDPV to those of methamphetamine. In a standard stimulant evaluation, the animals were allowed to intravenously dose themselves by pressing a lever. As expected, the rats steadily self-administered each drug whenever possible. To quantify the rats' level of desire, the scientists altered the experiment so that the rodents could only get another dose by making incrementally greater numbers of lever presses.

"When we increased how many lever presses a rat would have to emit to get an additional infusion of drug, we observed that rats emitted about 60 presses on average for a dose of METH but up to about 600 for MDPV—some rats would even emit 3,000 lever presses for a single hit of MDPV," explained co-author Shawn M. Aarde, a Scripps research associate. "If you consider these lever presses a measure of how much a rat will work to get a drug infusion, then these rats worked more than 10 times harder to get MDPV."

The researchers also observed the rats performing the obsessive-type behaviors associated with meth and bath salts use - analogous to teeth-grinding and compulsive skin-picking.

"One stereotyped behavior that we often observed was a rat repeatedly licking the clear plastic walls of its operant chamber - a behavior that was sometimes uninterruptable," said Aarde. "One could say MDPV turned some rats into 'window lickers' of a sort."

Taffe noted that the drug appears to only be growing in popularity since their experiments, and criminalization of the drug has spawned first-generation derivatives that will also need studying. He said he hopes to be able to anticipate how future bath salts derivates will affect the brain.

"We'd like the ability to predict, for example, which ones have the highest abuse potential, which are more likely to have long-term toxicity issues, and which carry high risks of acute lethal consequences," Taffe said.