By Matthew Davis
BBC News, Washington
Pressure to succeed on the sports field or simply to look "better" is driving a growing number of US children to abuse steroids.
There is concern that young girls are taking steroids to get a toned look
Latest estimates suggest more than a million high school students in the country have tried the body-altering drugs - nearly six times the number just 10 years ago.
Among the users are an increasing number of girls - some as young as nine - who are taking steroids to emulate the toned looks of movie stars and pop idols.
Experts say the phenomenon is due in part to children being pushed harder and younger than ever before.
'Cracking under strain'
Dr Marianne Engle, a psychologist with the New York-based Child Studies Centre, told the BBC: "There is tremendous pressure for kids to be successful in any accomplishment, to make their parents proud, to aim for a better life.
jumpiness and short temper
high blood pressure
liver, kidney, heart and prostate problems (less common)
increased sex drive
"Steroid abuse is an example of how our children are cracking under that strain."
Children are playing team sports in the US by the age of four. By the time they reach 10-years-old they may already be in elite competitions.
At top high school level, many are practically semi-professional sports stars facing huge pressure to perform, both for their communities and to win college scholarships.
"Today, sports figures are more revered than they have ever been," said Dr Engle.
"Some kids - and their parents - will do whatever it takes to get there."
'Winning at all costs'
Concern over steroid abuse among the young comes at a time when some of the biggest names in US sport are involved in a major drugs controversy.
Star athletes are role models for the younger generation
An investigation into a steroid distribution ring at the Bay Area Laboratory Co-Operative has put a number of elite athletes under suspicion of using banned drugs.
Meanwhile, a US congressional committee is looking into steroid abuse in sports.
Its chairman says his "primary focus" is on the message being sent to children who idolise and emulate professional athletes.
Congressman Tom Davis said: "I can only wonder how we've arrived at a place where the drive to win is more important to some than not cheating, or not risking permanent harm to your health."
Research suggests that young people are less likely to see steroids as harmful than they were 10 years ago, while getting hold of the drugs is becoming easier.
A black market exists in illegal anabolic steroids obtained from the gym or over the internet. One study suggests some parents and coaches may supply steroids to teenage athletes.
Equally alarming is research that suggests young girls may be using steroids as vanity drugs.
Dr Julian Bailes, a neurosurgeon at West Virginia University, says some 7.5% of ninth grade girls (aged 14 or 15) are using steroids.
He says they are taking low doses of the drugs, and do light workouts in a bid to lose fat and increase muscle tone.
Meanwhile, the sports medicine division at Oregon Health and Science University surveyed more than 4,000 students and found 2.6% of girls admitted using steroids.
Two-thirds of those girls were not athletes but young women looking for ways to get thin.
Another indication of the growing pressure on young people came in January 2005, when doctors announced an "alarming increase" in the numbers of child sports injuries.
The American Academy of Orthopaedic Surgeons said doctors treated more than 3.5 million children for sports injuries in 2003 and warned against treating young athletes as "merely small adults".
Former NFL player Steve Courson - a Superbowl winner who confessed to using steroids - says the whole mentality of youth sports needs to change.
"How can coaches teach valuable lessons about preparing youth for life when their value is based only on wins and losses?" he told a Congressional hearing last week.
Parents are also being urged to take responsibility.
Dr Bailes told the BBC: "What we are seeing is an explosion in the acceptance that steroids are necessary to succeed.
"We as parents need to redirect today's youth to what should be gained from sport - fair play, team spirit and success without cheating."