Meet Our Team

Medical Team

Joseph K. Thornton, M.D.

Dr. Thornton came to Greencastle in 1982 to help establish GFP with Dr. Hudzinski.  He is active in church work as a deacon in Grace Reformed Fellowship.  He enjoys gardening and other outdoor activities with his wife and nine children, who have all been home schooled.  Dr. Thornton has a degree in chemistry from the University of New Hampshire, a medical degree from Penn State University of Medicine and did complete his residency training at the Polyclinic Medical Center in Harrisburg, PA.  He also maintains his board certification in Family Practice.

Duane E. Sipes, M.D.

Dr. Sipes joined Dr. Hudzinski and Dr. Thornton in 1991. As a native of St. Thomas he grew up in the area, graduated from Shippensburg University with a biology/pre-med degree, and then received his medical degree from Penn State University College of Medicine at Hershey. He then completed a Family Practice Residency in Kingston, PA. He is board certified in Family Practice and enjoys gardening and outdoor activities with his wife and five children.

Nathan Derstine, D.O.

Dr. Derstine is a graduate of Eastern Mennonite University and went on to medical school at Philadelphia College of Osteopathic Medicine.  He completed his residency in Family Practice at Altoona Hospital before joining Greencastle Family Practice.  Dr. Derstine has a special interest in pediatrics, sports medicine, and travel medicine.

Michael S. Fitzpatrick, D.O.

Dr. Fitzpatrick is a graduate of Grove City College.  He went to medical school at the Philadelphia College of Osteopathic Medicine.  He did his residency training in Pittsburgh at St. Margaret Hospital, and an additional year of training in Johnson City, TN where he had training in endoscopy.  He joined the staff at Greencastle Family Practice in 2008.  Special interests include pediatrics, sports medicine, medical procedures including colonoscopy, as well as medical missions.  He is an active member at Grace Baptist Church in Chambersburg, PA.

John Strickler, P.A.-C.

John Strickler has recently joined Greencastle Family practice as a physician assistant.  He was born and raised in Edenville in a family of ten and was home schooled through high school.  After working in landscaping, construction and as a draftsman for four years, he studied biology and biochemistry at Millersville University. He graduated from Marywood University in Scranton PA in 2014 with a masters degree in physician assistant studies.  In his spare time, John conducts a local youth chorus and enjoys tennis, volleyball and bicycling.  He is a member of the Old Order River Brethren church in Edenville, PA

Mindy Barnhart, CRNP.

Mindy Barnhart is born and raised here in Greencastle.  She received a Bachelor of Science in Nursing from Shepherd (College) University in Shepherdstown, WV in 2000. Her clinical experience as a Registered Nurse has been in the hospital setting mostly in the Emergency Department. She went on to earn a Master of Science in Nursing from Walden University in Minneapolis, MN in 2014. She is certified as a family nurse practitioner through the American Academy of Nurse Practitioners. In June 2016, she joined Greencastle Family Practice feeling blessed to give back to the community that she grew up in of Greencastle!

Candace Deverell, CRNP

Candace Deverell received her Associate of Science in Nursing from Hagerstown Community College in Hagerstown, MD. While working as a registered nurse she returned to school and earned her Bachelor of Science in Nursing from Penn State University in State College, PA. Her experience as a registered nurse included emergency care, sexual assault forensic examination, and school nursing. She went on to earn her Master of Science in Nursing from Shenandoah University in Winchester, VA. While at Shenandoah University, Candace was inducted into the Sigma Theta Tau International Honor Society of Nursing. Candace maintains her certification as a family nurse practitioner through the American Academy of Nurse Practitioners. She resides in Greencastle, PA, with her husband and two daughters.


Kent Copeland, M. D.

Dr Copeland is a career Family Practice physician who has recently moved back to Pennsylvania, his childhood home, and is happy to join the Greencastle Family Practice.  Kent is proud to have served in the US Medical Corps, as well as overseas in medical ministry. He has a special interest in thyroid and autoimmune disorders but is fascinated with all aspects of family medicine. Kent loves playing sports and board games, strumming a guitar, and seeing his family grow – with 5 grown kids and his 2nd grandchild on the way.  He is especially fond of Christian apologetics and has been a follower of Christ for over 5 decades. Other than English, he speaks pretty good Khmer and a smattering of Spanish.

Counseling and Psychological Team

Paul D. Bitner, M.S.

Mr. Bitner joined the Greencastle Family Practice in 1990 and is a Licensed Professional Counselor. He graduated from Bryan College in 1980, with degrees in Psychology and Greek. He then earned a Master of Science in Community Counseling from Shippensburg University in 1989. He works with individuals, couples, and families, with anxiety and mood disorders, traumatic histories, and family stressors. Mr. Bitner is a trained EMDR therapist, specializing in helping people struggling with traumatic events. He also is a counselor for a group home, Hosanna House, in Belize for teens with abuse and neglect issues. He is married and the father of four children and two son-in-laws. He enjoys growing fruit and many outdoor activities.

Melissa Grove, M.S., LPC

Melissa Grove began with the practice in October 2013. Melissa is a LPC in PA and a Nationally Certified Counselor. She graduated from Shippensburg University with a double major in Sociology and Psychology. In 2002, she completed her Masters degree in Mental Health Counseling.

Melissa has experience working with a variety of populations. She has counseled individuals, families, and facilitated groups. Melissa has concentrated her continuing education in play therapy. She works with children individually as well as with children and their parents through Filial Play therapy.

Melissa is married and has 3 children. She enjoys spending time with her family and outdoor activities.

Debra Main, M.A.

Debra Main joined Greencastle Family Practice Counseling Services in June 2007. A native of Tennessee, she is a wife, mother, grandmother and identical twin. She enjoys reading and gardening in her free time, as well as anything related to being “Nana” to her five grandchildren. She is active in her church and is passionate about small group ministry.

Debbie is a graduate of Central Michigan University where she studied psychology and business. She completed her Master of Arts Degree in Counseling at Oakland University in Rochester, Michigan with post-graduate studies in children and adolescent counseling as well as stress and trauma care. She is also a Board Certified Life Coach specializing in leadership and marriage coaching.

Nancy Morton, MSW, LCSW

Nancy Morton is a Licensed Clinical Social Worker who earned her Bachelors degree from Shippensburg University and her Masters degree from Widener University. She first joined Greencastle Family Practice in 2005 and later took a couple years off to serve as a missionary in central Asia before returning in 2010.

Nancy feels very blessed to be part of the GFP family where she counsels children, adolescents, adults, couples, and families.  She enjoys the privilege of walking alongside people as they seek to overcome depression, anxiety, trauma, and relationship issues.  Her special interests include Christian counseling, play therapy, and teen issues.

She enjoys a variety of outdoor activities with her husband and their three children.

Diane Swan, M.S., L.P.C.

Diane Swan is a Licensed Professional Counselor in Pennsylvania, as well as a Nationally Certified Counselor.  She received her Master’s Degree in Mental Health Counseling in 2006 from Shippensburg University, and has been a counselor at Greencastle Family Practice since 2008.


Diane has experience working with all ages and populations in an expansive range of mental health issues and life stressors.  She specializes in helping people heal from past abuse and trauma, overcoming depression and anxiety, family systems therapy, marital counseling, drug and alcohol counseling, and mental health issues related to attachment disorders.  Diane is passionate about utilizing Christian Based Counseling for clients that are seeking healing and spiritual guidance through biblical principles.


Diane lives with her husband and their five children in the scenic outskirts of Chambersburg Pennsylvania.

Cheryl Sears, LPC, LMHC

Mrs. Sears relocated back to the Chambersburg area and joined GFP in 2016.  She graduated from Nyack College in 1985 with degrees in Psychology and Business.  She earned a Masters in Professional Counseling at Liberty University in 2010.  She is a licensed counselor in NY and PA., working with individuals, couples and families with anxiety and mood disorders, traumatic histories, and family stressors.  Mrs. Sears is a trained EMDR therapist specialiszing in helping people struggling due to past traumatic events.  She has worked extensively with troubled children and teens and their families.  She is married and the mother of three children and one son-in-law.  She enjoys playing piano and singing as well as landscaping.