Collette, here's a random, short article refuting your therapist's claim:
https://www.psychologytoday.com/blog...ction-recovery
Neuroplasticity is well established. There are practices designed specifically to help rewire the brain (which is to say, develop new neural pathways and thus new habits). Check out anything by Rick Hanson, for examples, especially the book
Hardwiring Happiness.
AVRT, whether deliberately or not, utilizes this concept. By repeatedly saying I will never drink again, and by repeatedly refuting (rather than surrendering to) the AV, we are literally strengthening neural pathways that will help wire our resolve into our brains.
Aside from certain types of brain trauma (such as caused by an impact or concussion), the brain can heal. If addiction is a disease, neurobiologists tend to agree that it is not permanent, though returning to old behaviors (using) can reactivate dormant pathways and quickly return people to old patterns.
That's part of why a commitment to forever works better than one day at a time. Close that door and wire it shut yo.