Most scientifical research towards brain damage and drug dependence is focused on nandrolone; one of the most commonly (ab)used AAS. Nandrolone is a synthetic modification of the testosterone molecule and lacks a methyl (CH3) group at the C19 position.
Apart from elite athletes aiming for increased performance during competition, both professional and amateur bodybuilders administer AASs to gain maximal muscle volume. During the past decade their use has spread to colleges and high schools as well. Over the last years, several studies examining substance use-patterns have shown an increase in anabolic-androgenic steroids (AASs) in all user groups, not only in athletes. The use of AASs is no longer limited to professional power training athletes and body builders, but a large number of young adolescents take AASs in high doses with the intention of improving their physical fitness, appearance, increasing of confidence levels, and even pleasure.