Why are healthy cells killed due to steroids use?

You know that steroids are administrated by different athletes in order to enhance muscle size and energy. But according to late studies, taking of steroids is a too harmful aspect for brain cells. Since these drugs induce amount of testosterone in body, they affect and even kill brain cells. This confirmation about destruction of brain cells by increased amount of testosterone was approved by a study leaded by Yale School of Medicine that was published in the Journal of Biological Chemistry.
Scientists say that increased aggressiveness manifested by steroids consumers testify that certain amount of brain cells was disturbed due to taking of steroids.
Barbara Ehrlich, a professor, a leader of a study related to steroids use, recommends not to condemn those who apply steroids, if they act unusually. It is important to know that it can be not their blame. Steroids must have been responsible for aggressive manners of those who apply these products.
The study leaded by Yale School of Medicine approved that testosterone killed nerve cells. One of chief functions of testosterone secreted naturally is following: to destroy nerve cells which can be harmful for the whole body due to their damages. But when level of testosterone is enhanced, it destroys not only destructed cells but healthy ones too. It may lead to such serious troubles, as appearing of Alzheimer's and Huntingdon's disease and others.

Aggressiveness of hamsters due to steroids
Hamsters were recruited in one of studies published in the journal Behavioral Neuroscience. The scientists participated in the study observed influence of anabolic steroids upon the hamsters. The hamsters that were given these drugs became too aggressive. Their brain activity was changed a lot due to these preparations.
The specialists made a conclusion that steroids damaged people’s brain the same way as hamsters’ brain. According to their confirmations, people suggest that steroids are forbidden due to their athletic effects. But they should realize that the chief reason is harmful influence of these medications upon human health. Steroids must be used only for treatment of diseases by prescriptions of pharmacists. Steroids use in sports should be forbidden totally.