An imaging study of the brains of long-term users of anabolic-androgenic steroids has found significant brain structural and functional abnormalities, according to a team of HMS researchers at McLean Hospital. Their findings appear in the July issue of Drug and Alcohol Dependence.
Although studies have been published on the cardiovascular, endocrine, and cognitive effects of long-term steroid use, this is the first time researchers have been able to systematically examine changes in the brain from use, says Marc Kaufman, an HMS associate professor of psychiatry, director of the Translational Imaging Laboratory at McLean, and a co-author of the article. The imaging modalities used included MRI, which focuses on brain structure; fMRI, which measures brain activity; and MRS, which looks at levels of different chemicals in the brain.
One of the key findings from the structural imaging data, says Kaufman, centered on the amygdala, the region of the brain involved with emotion regulation, aggression, anxiety, and possibly, depression. This structure was more than 20 percent larger in participants who were chronic steroid users than in nonusers.
The study uncovered another abnormality among steroid users: a decrease in the brain levels of a sugar known as scyllo-inositol, which is key to preventing neurotoxic proteins from clumping, particularly beta-amyloid proteins, which are known to play a role in the development of Alzheimer’s disease and other forms of dementia.
“Anabolic steroids are the newest of the world’s major forms of drug abuse,” says Harrison Pope ’74, an HMS professor of psychiatry, co-director of the Biological Psychiatry Laboratory at McLean, and article co-author.
“Widespread use of steroids did not appear until the 1980s in the United States, so this is a very young form of substance abuse in contrast to other drugs like marijuana and opiates that have been around for thousands of years.”
According to Pope, it is estimated that 3 to 4 million U.S. individuals have used steroids at some time in their lives, with approximately one-third continuing to take steroids for long periods of time, often in spite of the adverse effects.