Hrm...
Do you really think that's true? I remember the guy that got shot along with Regan, his personality changed 180% afterwards. Plenty of folks suffer strokes and have other neurological changes and their personalties change.
Let's say Brady was a funny guy before the shooting, and after he was a totally serious dude... Who is/was the real Brady? I'd say the guy before the damage was the true personality, and that the damage impaired the machine (brain = chemical machine) that allowed him to communicate etc.
For me, I feel that anxiety is a disease, just like any other that can effect you neurologically, like Alzheimer's etc - something has gone wrong in the brain, nervous systems, endocrine system, gut flora (who knows) and signals for fight & flight are either over-sensitive, sensitive to the wrong stimuli, always on, over-react etc. This is not 'me' - this is a disease.
Put it this way, if you were on the Starship Enterprise - and you went to Dr. Mccoy - would he scan you and say - o wow, I see you're freaking out three times a week, that's normal - back to engine room you... Or would he say, hey - something is going on here, your cortisol is raised, and you're laying on the deck crying every few days - let me fix that chemical imbalance for you.
The idea that everything related to anxiety is environmental in nature (caused from historical experience, or the way you deal / think / react to the world and if you can only find the right toolset to change your thinking, it will go away - seems farcical to me. I have a cousin with Down syndrome, I could sit with him all day and tell him to try to think his way out of that and not too sure it's gonna work.
Sure, finding mental coping mechanisms, looking at whole picture, reframing, clenching, relaxing technics - these can help you deal with anxiety. But in my case (at least) - something from birth was turned on, over-sensitized or whatever - and I am hard wired to freak out and live with anxiety. As someone who seems to have dealt with the same thing I respect it's working for you.
Some things do help me - like biofeedback has taught me to lower my HR, practicing breathing insures I don't hyperventilate, clenching my fists and relaxing them soothes the buildup, looking 'up' lowers HR, mantras help.. But panic attacks (for me) come out of a clear blue sky 99% of the time. I can be watching 'Love Island' and eating some chips happy as clam and next second - my head is on fire... There's no 'me' in that - it's only the disease.
I'm sure oneday there will be a cure for anxiety, once they figure out what gone wrong in the brain or body. I think it's physical not mental. My 5yo self was physically sick, not mentally sick from my environment - was I denied milk, did a dog scare me, did I think the mobile over my crib was falling? Meh.. physical screw up somewhere in body.
My girlfriend is an asian with blue eyes, we've DNA tested her, 100% pure... Mutation happen as a matter of course. I don't think bi-polar, Schizophrenia, malignant narcissism, are conditions that can be cured from 'right thinking'
Peace