Dopamine Transporter Density Reduced in Psychostimulant Users

In laboratory animals, chronic psychostimulant abuse has been shown to produce long-term, if not permanent, damage to dopamine neuronal integrity. Using functional brain imaging, these researchers sought to quantify dopamine transporter and receptor density in living humans with a history of drug abuse. PET studies were performed on 10 normal control subjects, 6 abstinent methamphetamine users, 4 abstinent methcathinone users, and 3 patients with Parkinson's disease (PD). Urine and blood toxicology screens ruled out recent drug use; subjects had been abstinent for approximately three years.

Compared with controls, the abstinent methamphetamine and methcathinone users exhibited significant decreases in dopamine transporter density in the caud…