Australasian Science Magazine

By Stephen Luntz

The effects on rats of mephedrone, better known as the party drug meow meow, indicate that for once the hype about a drug’s addictive effects might be accurate.

University of Sydney PhD student Craig Motbey used protein tracking to determine the parts of the rat brain activated by mephedrone. “When you look at the pattern of neurons activated by the mephedrone, it is as if the effect of ecstasy and the effect of methamphetamine on the brain’s neurons had been laid on top of each other,” he says.

“The findings confirm the anecdotal reports from mephedrone users that the drug combines the euphoric, sociable effects of ecstasy with an addictive hook comparable to drugs such as that

Users report meow meow, unlike ecstasy, stimulates a desire for a new dose within an hour. Motbey says that “surveys taken in the UK, where the drug has been widespread for longer, indicate that almost half of users consider it at least as addictive as cocaine”.

Motbey’s rodents seem to agree, seeking further doses frequently. However, Motbey says: “We didn’t notice any withdrawal symptoms once the drug was taken away, although that wasn’t something we were particularly looking for”.

Chemically mephedrone is similar to the amphetamine family, although its closest amphetamine relative is unknown as a recreational drug. Motbey says the similarities to ecstasy, that it is “pro-social and makes touch feel nice”, are chemically more of a coincidence, and the effects are very different from taking an ecstasy/amphetamine combination.

Meow meow is too new for there to be conclusive proof of brain damage, but Motbey says: “The redosing itself is a danger – how you time your dosage of a drug is almost as important as how much you have”. Animal studies have found lasting changes to the serotonin system, but only with high doses in warm environments.

However, subsequent depressive effects, nicknamed “eccy Monday” by ecstasy users, seem likely. Motbey adds: “We can confidently state mephedrone can induce strong anxiety”.

Mephedrone is decades old, but only recently hit the party scene. Motbey says: “You need to be a competent chemist to produce it, but you don’t need to be a Nobel Prize winner”. His own lab was donated a portion of a large Customs seizure, rather than being forced to synthesise it themselves.

The findings were published in Addiction Biology.