COCAINE HURTS BRAIN'S PLEASURE CIRCUITS IN STUDY

NEW YORK - Chronic cocaine use harms brain circuits that help produce the
sense of pleasure, which may help explain why cocaine addicts have a higher
rate of depression, a study suggests.

It's not clear whether cocaine kills brain cells or merely impairs them, or
whether the effect is reversible, said the study's author, Dr. Karley
Little. But it's bad news for cocaine addicts in any case, he said.

"I personally wouldn't want to lose 10 [percent] or 20 percent of my
reward-pleasure center neurons, or have them just deranged or not working
right," said Little, of the Ann Arbor, Mich., Veterans Affairs Medical
Center and the University of Michigan.

He and colleagues studied brain samples taken during autopsies from
long-term, heavy cocaine users.

Their results were reported in the January issue of the American Journal of
Psychiatry.

Little said the research did not reveal whether the brain impairment
resulted from years of use or just recent use before death. Stephen Kish,
head of the human brain laboratory at the Center for Addiction and Mental
Health in Toronto, said researchers have "always considered cocaine to be a
dangerous drug" because of its potential for addiction and harm to the heart.

"We now have to add to the list [of risks] a damaging effect of cocaine on
the brain, which was something we never expected before," Kish said.