I would like to express my sincere appreciation to my Developmental Editor, Gary O'Brien who, as always, has provided invaluable guidance throughout the development of this edition. In truth, Gary should share authorship with me on this project. Through his efforts he has demonstrated ownership and a personal investment in making this text the best it can be. His input, patience with me, and dedication to this project has been indispensable and I truly respect his opinions and direction on all of our projects. I would be hard pressed to complete any of our projects without his help. I would also like to express my gratitude to my Product Developer, Alexander Preiss, my Content Product Manager Danielle Clement and the Content Licensing Specialist: Jacob Sullivan for navigating this textbook revision through McGraw-Hill.
I would like to thank two individuals Dr. Johna Register-Mihalik and Dr. Amy Sauls, both of whom are my colleagues at the University of North Carolina at Chapel Hill, for their help in reviewing the sections on concussion and pharmacology, respectively. Their input and suggestions have been most helpful in this revision.
Finally, I want to thank my wife, Tena, and our sons, Brian and Zach, for their enduring support and encouragement. They constantly help me to keep my perspective on both my professional and personal life.