I am well aware that there are chemicals in the brain that affect what we do but to say those chemicals make us do certain things so as to negate free will is taking it a step too far. Can you cite something to prove this?

How would drug addicts who successfully give up their addictions fit into your scenario?

Once one is chemically addicted to a drug it has great control over your brain and makes it extremely hard to give it up and even makes you feel sick for awhile before your body can rebalance itself.

Godspell