They are similar in some ways. As you said both here and in your comments in my other post, they both have a stable "Zen" quality about them and they both go through phases of drug abuse.
But I see the underlying forces as quite different.
Ben's main destabilizing factor is anger.... anger at his former partner, anger with himself, anger with his disease, anger with society. I can't imagine Blake ever throwing punches during the vigil.
Blakes's main destabilizing factor is his low self-esteem. He has trouble seeing himself as lovable or competent.
Ben and Blake do drugs for very different reasons. Ben uses the steroids with the hope that they will help him stay alive. His original intent is good. I see this situation as similar to people who take pain medication or prescribed stimulants in order to stay healthy and to function. You take the drugs despite the risks of addiction and hope for the best. I personally have to deal with my own chronic illness, so I can really empathize with Ben.
Blake, on the other hand, appears to take drugs as a form of escapism and "pain management."