I do believe that brain chemistry plays a role in the development or severity of anxiety. My favorite book on the topic was written by Eric R Braverman, MD and is titled The Edge Effect.
Dr Braverman describes the brain in terms of the actions of four neurotransmitters, dopamine, acetylcholine, GABA and serotonin. Readers take a series of quizzes to determine their main “type.” For example, GABA types are traditionalists, Serotonin types the artisans, Dopamine types rational thinkers, Acetylcholine types intuitive thinkers.
He then describes the symptoms of imbalances of each hormone and goes on to explain what can be done to correct these. Solutions are presented in this order of importance: diet and exercise (specific to the type), vitamins and supplements (also specific) and as a last recourse, prescription medications.
I like this book because, when you take the quizzes, you get your own road map for dealing with your brain imbalances.
Check it out for yourself.