The following are books I have found very useful. To order from Amazon.com, just click on the title.

This book addressess the issues of the 20% of the population with very sensitive physical nervous systems. It validates sensitive people rather than pathologizes them. It helps to understand the challenges of high sensitivity while also realizing the strengths of this trait.

This book addresses the physical systems in the body that contribute to a brain that doesn't function well. While it doesn't discourage the use of medication when it's necessary, it does advocate addressing overall physical wellness. Very thorough.