how can drugs affect the brain?
 The effects of drugs on the brain depends on the drug itself. Heroin makes the brain dependent on it, while marijuana can effect emotions, memory, and judgment

how can steroids affect our body?
Anabolic steroids are artificial versions of a hormone that's in all of us -- testosterone, this things make your testicles smaller, because of steroids replace tetestorene, and testosterone make yours testicles grow. (That's right, testosterone is in girls as well as guys.) Testosterone not only brings out male sexual traits, it also causes muscles to grow. Some people take anabolic steroid pills or injections to try to build muscle faster. ("Anabolic" means growing or building.)

how what are club drugs? 
club drugs are those that was sell by night clubs and bars, this drugs unlike street drugs are much expensive and are very well presented at diference than street drugs that are poor precented.

what can they (club durgs) do to our body?
Club drugs have varying effects. Ketamine distorts perception and produces feelings of detachment from the environment and self, while GHB and rohypnol are sedating. GHB abuse can cause coma and seizures. High doses of ketamine can cause delirium and amnesia. Rohypnol can incapacitate users and cause amnesia, and especially when mixed with alcohol, can be lethal.