Addiction and Causation

Is it possible for a compatibilist to capture the notion of a choice that is resistible but very, very hard to resist? And, along the same lines, is it possible for the compatibilist to capture the notion of degrees of responsibility, of greater or lesser moral responsibility? Of course, duress may lessen responsibility, and in general the aversiveness of the alternatives facing an agent may lessen her responsibility for an action: The more aversive the alternatives, the less responsible the agent-or at least the less inclined we are to punish the agent. That way of ranking responsibility is clearly intelligible in compatibilist terms.