TUESDAY, Dec. 13 (HealthDay
News) -- The use of anabolic steroids to improve
performance has rocked the world of amateur professional
sports, and a new animal study suggests these
performance-enhancing drugs may also be addictive.
When given the choice,
hamsters voluntarily infused themselves with powerful
anabolic steroids, researchers report.
This may mean that "what
makes animals feel good when they take steroids is their
effect directly on the brain," said lead researcher Ruth
Wood, a professor of cell and neurobiology at the
University of Southern California. "It's not because it
makes them bigger and stronger. Steroids are not just
acting below the neck."
steroids are commonly abused by athletes and
bodybuilders. Steroids were banned from Olympic
competition in 1975, and were labeled controlled
substances by U.S. officials in 1991.
One 2002 study by
researchers at the University of Michigan found that the
lifetime incidence of steroid use among high school
seniors was 4 percent -- comparable to that of crack
cocaine (3.8 percent) or heroin (1.7 percent).
There are a lot of
complicated reasons why people take steroids, Wood said.
"They take steroids to improve their athletic
performance or change their body shape," she added. "But
an animal has none of these motivations. They will
voluntarily take steroids, which indicate to us that
perhaps steroids are addictive."
Her team's findings were
presented Tuesday at the American College of
Neuropsychopharmacology's annual conference in Waikoloa,
In their experiments,
Wood's team implanted hamsters with small portals for
the self-administration, via a simple device, of
commonly abused steroids directly into their brains.
When the hamster
activated the portal it received either a microgram of
testosterone, or one of several commonly abused
steroids: nandrolone, drostanolone, stanozolol or
Wood's team found the
animals had a preference for testosterone and the two
most powerful steroids, nandrolone or drostanolone. The
hamsters did not voluntarily inject the weak steroids
stanozolol or oxymetholone.
The findings suggest
that steroids may be addictive, Wood said.
"Steroids may cause
dependence, which may make it difficult for people to
quit. For people who are chronic users, we may need
better strategies to stop them [from] taking steroids,"
One expert isn't
convinced that steroids themselves are addictive, or
whether humans seek secondary benefits, such as muscle
"There is not enough
data showing primary reinforcing effects of
androgenic-anabolic steroids," said Bruce Svare, a
professor of psychology and neuroscience at the State
University of New York and director of the National
Institute for Sports Reform. "Just how much of the
effects of androgenic-anabolic steroids in humans are
primary reinforcing and how much are secondary
reinforcing is unknown."
"Some [humans] report
euphoria and a sense of invincibility, but it does not
approach the positive hedonic effects of classic drugs
of abuse like heroin and cocaine," he noted.
"My presumption is that
androgenic-anabolic steroids use in humans is still
largely driven by secondary reinforcing effects, but
there also may be some primary reinforcing effects as
demonstrated by the author of this paper," Svare said.
Another expert thinks
that even the hint that steroids might be addictive is
another reason to clamp down on their use.
"This finding gives us
one more reason to address steroid use by professional
athletes as a matter of societal urgency," said Dr.
David L. Katz, director of the Prevention Research
Center at Yale University School of Medicine.
"Steroid use is not a
minor matter of private choices by grown-ups willing to
accept certain consequences for certain gain," Katz
said. "Steroid use is a bona fide medical hazard, and a
potentially addictive one at that. A nation of
responsible adults, with the well-being of their
children in mind, should do everything required to
banish the practice."
For more on the dangers
of steroid abuse, head to the
American Academy of Pediatrics.
SOURCES: Ruth Wood, Ph.D., professor, cell and
neurobiology, University of Southern California, Los
Angeles; Bruce Svare, Ph.D., professor, psychology and
neuroscience, State University of New York, Albany, and
director, National Institute for Sports Reform; David L.
Katz, M.D., M.P.H., associate professor, public health,
and director, Prevention Research Center, Yale
University School of Medicine, New Haven, Conn.; Dec.
13, 2005, presentation, American College of
Neuropsychopharmacology annual meeting, Waikoloa, Hawaii