Steroids and the brain

[akali]

Hello all, I am writing a report in my university about the effects of steroids on the brain. I am having a rather hard time depicting the actual truth because articles i have read seem to contradict one another. I figured this forum would be a good place to ask as i am finding mixed information, does many of the generic testosterone steroids many bodybuilders, athletes , etc use have the capability to lower or impair ones mind? Yes this may seem to be a stupid question but im trying to depict whether steroids can have negative effects on the mind other then irritability, aggression etc. Can it lower ones cognitive functions, and impair deep thought, can it make you feel or seem dumber, or smarter even.