Neuronal depletion in the globus pallidus of heroin addicts.

Decreased neuronal population densities are described in the globus pallidus of narcotic addicts. Toxicologic studies indicate mixed addiction to be frequent, but exposure to parenteral heroin is the only common factor. This permanent brain damage seems more likely to be caused by recurrent episodes of hypoxia during severe reactions to narcotics than to be related to direct neurotoxic effects of heroin. The lesion may account for some of the long term changes observed in addicts.