Dr. C.J. Malanga, an associate professor of neurology, pediatrics and psychology at the University of North Carolina School of Medicine, said mephedrone and other potentially addictive stimulants "inappropriately activate brain reward circuits that are involved in positive reinforcement. These play a role in the drug 'high' and compulsive drug taking."
Malanga said a study of laboratory mice used intracranial self-stimulation, a technique developed in the 1950s that can measure a drug's ability to activate reward circuits. Animals were trained to perform a task -- spinning a wheel -- to receive a reward, or directly stimulating of the brain pathways involved in reward perception.
During the study, adult animals were implanted with brain stimulating electrodes. Measures of their wheel spinning effort were made before, during and after they received various doses of either mephedrone or cocaine.
The study, published in the journal Behavioural Brain Research, found the effects of mephedrone on the brain's reward circuits were comparable to similar doses of cocaine.
"As expected our research shows that mephedrone likely has significant abuse liability," Malanga said in a statement. "It increases the rewarding potency of intracranial self-stimulation just like cocaine does."