There needs to be an exploration of addiction and rationality. Gamblers are addicted; we know some of the brain mechanisms of addiction -- some neurotransmitter A is released in brain region B, Causing C to deplete, causing a dependency on the reward that A provides. This particular neuro-chemical circuit derives great utility from the addiction, thus driving the behaviour. By this argument, perhaps one might argue that addicts are "rational", because they derive a great utility from their addiction. But is this argument faulty?

A mechanistic explanation of addiction says the addict has no control, no free will, no ability to break the cycle. But is it fair to say that a "machine has a utility function"? Or do you need to have free before you can discuss choice?