NEW research into the long-term effects of anabolic steroids suggests they may have hazardous effects on memory.
Professor Harrison Pope, one of the world's leading experts on the effects of steroid use - and a former weightlifter - is involved in pioneering research both at Teesside University in Middlesbrough and Harvard Medical School in America.
In Middlesbrough, he has been working with drug and alcohol charity Lifeline and Teesside University to examine whether long-term use of high doses of anabolic steroids might affect cognitive functions and the heart.
Prof Pope said: "Where the individual is required to remember the appearance of a particular shape or pattern presented on a computer screen, or to remember the location where a particular pattern had previously appeared, the steroid users performed significantly less well than the non-users."
In a recent laboratory study in Italy, rates given large doses of steroids developed difficulties with their spatial memories.
"At the least, more research is urgently needed to address this question," he added.
Prof Pope has been researching the effects of steroids for more than 25 years.
He has published more than 300 scientific papers in psychiatry and medicine and spoken at conferences worldwide.
One of his most famous research projects looked at the popular Action Man toy and how it has grown steadily more muscular over the last several decades.
Prof Pope said: "Steroids are one of the newest forms of drug use. Steroids were only discovered about 70 years ago. Initially used only by elite athletes and bodybuilders, it was not until the 1980s and 1990s that we started to see widespread use of steroids in the general population."