Not Convinced That Your Thoughts Can Make You Sick Or Heal You? Then Read:

Anatomy of an Illness as Perceived by the Patient by Norman Cousins:
http://www.amazon.com/exec/obidos/ASIN/0393326845

Why Animals Don't Get Heart Attacks but People Do
by Matthias Rath M.D.:
http://www.amazon.com/exec/obidos/ASIN/0967954681

Head First: The Biology of Hope and the Healing Power of the Human Spirit
by Norman Cousins:
http://www.amazon.com/exec/obidos/ASIN/0140139656