WEDNESDAY, April 12, 2006 (HealthDay News) -- Amphetamines appear to have a greater effect on male brains than female brains, a new study suggests.
"These appear to be the first clinical studies whose results may help explain why we see a greater number of men abusing amphetamines than women," study leader Dr. Gary S. Wand, professor of endocrinology at Johns Hopkins School of Medicine, Baltimore, said in a prepared statement.
The finding could also help in the development of tailored treatments for drug abuse and neurological diseases, the researchers said.
Wand's team used PET scans to observe the brains of 28 men and 15 women, ages 18 to 29. The study found evidence that, compared to women, men's brains released up to three times the amount of the neurotransmitter chemical dopamine when exposed to amphetamines.
Dopamine -- linked to the brain's pleasure system -- can increase heart rate and blood pressure and plays a critical role in the brain's control of movement. Drugs such as amphetamines and cocaine trigger the release of dopamine. Dopamine shortages are associated with memory loss, Parkinson's disease, depression and other mental illnesses.
In 2004, 6 percent of American males and 3.8 percent of females, 12 and older, illegally used amphetamines, according to the U.S. Substance Abuse and Mental Health Services Administration.
The findings may also explain the higher incidence of amphetamine-induced neurotoxicity in males compared to females, Wand said.
The study is expected to be published in the July 1 issue of the Journal of Biological Psychiatry.
The U.S. National Library of Medicine has more about amphetamines.