Dr. Thistlethwaite is a graduate of the West Virginia University School of Medicine and completed his residency in Psychiatry at Charleston Area Medical Center. He is certified by the American Board of Psychiatry and Neurology, he is a fellow of the APA, and has worked in private practice as a psychiatrist for the past 30 years. Dr. Thistlethwaite is a member of the American Psychiatric Association. Dr. Thistlethwaite currently serves as an Assistant Clinical Professor of Psychiatry at West Virginia University.

Prior to focusing exclusively on outpatient psychiatry Dr. Thistlethwaite served as Chief of Psychiatry for Thomas Memorial Hospital. Dr. Thistlethwaite also provides TMS (Transcranial Magnetic Stimulation) Therapy Services, as well as Spravato Therapy. Dr. Thistlethwaite completed a visiting fellowship in Transcranial Magnetic Stimulation (TMS) at Duke University in 2013. He has been certified as a Brainsway dTMS system operator. He completed Neuronetics training program for TMS in 2012.