There's addiction and then there's addiction.
Even with the most addictive drugs, some people can take them once and walk away while other people will never be able to leave them alone.
Some guys get addicted to the feeling of power and strength that steroids give them. Some guys have body issues and get addicted to trying to make themselves look a certain way. But steroids don't get into your system and make you have to have them. At least, not to the best of my knowledge.
I could be wrong (and CnD will tell me if I am

) but I don't personally consider steroids very addictive. Much less addictive than alcohol or meth or crack or heroine or smoking. Because, like Thunderkyss was kinda saying, with steroids the addiction comes from a probably pre-existing mental condition that the steroids feed into while alcohol and drugs can actually make your body chemistry almost REQUIRE those chemical compounds in addition to mental conditions that they may also be feeding into. (TKyss wasn't saying that last part and was actually kinda taking the stance that addiction is all in your head, which is categorically wrong.)
Cush may have been doing steroids since he was a teenager (although frankly, I'd expect him to be a lot shorter if that were the case) but just the fact that he can go an entire season without taking them seems to deny any possibility of addiction to them.