Dr. Diana Sjostrom has 32 years of experience in private practice treating people struggling with depression, anxiety, and stress-related illnesses. She also has been counseling couples, families, and pre-marital relationships. Sjostrom is a certified bioenergetic analyst; she understands how the body is the outer expression of the unconscious and how this can be related to health and relationship issues in marriage. She works with individuals and couples to find resolution to unresolved emotional and thinking conflicts.

Dr. Kim Schaeffer has served in PLNU's Department of Psychology since 1989, as department chair from 1996 to 2001 and acting-chair during 2006. He completed his Ph.D. in biological psychology from the University of Oklahoma Health Sciences Center and his Ph.D. equivalent in clinical psychology from Oklahoma State University (OSU). Prior to joining PLNU, Schaeffer completed his clinical psychology internship at the VA Medical Center in Memphis, TN.

Dr. Joel Sagawa is a licensed clinical psychologist (PSY 23683) who began at PLNU in 2016. He received his doctorate in clinical psychology and master’s degree in theology from Fuller Theological Seminary. Prior to joining PLNU, Sagawa worked in college mental health for nearly 10 years, proving psychological services at Azusa Pacific University and the University of Southern California.

Dr. Ross Oakes Mueller began teaching at PLNU in 2007. He is married to Dr. Kendra Oakes Mueller, with whom he has four children: Nolan, Nash, Nora, and North. His research and teaching interests lie in the domain of moral psychology and character development. He and Dr. Leffel currently advise students who research the formation of virtues, including gratitude and empathy, among others.

Dr. Kendra Oakes Mueller began teaching courses at PLNU in 2007. Prior to joining PLNU, she worked in university counseling centers, providing individual, group, and couples counseling to undergraduate and graduate students at Azusa Pacific University and the University of San Diego. She is a licensed clinical psychologist and continues to perform psychological assessments and provide supervision for clinicians in training.

Dr. G. Michael Leffel has been teaching at PLNU since 1992. Prior to joining the Department of Psychology, he was a psychotherapist in private practice in Denver, Colo. His specializations include personality psychopathology, psychoanalytic psychology and psychotherapy, and the integration of psychoanalytic developmental theory and spiritual formation. As a PLNU Wesleyan Center Scholar and Fellow, Leffel is currently working on several books in the area of moral development and Christian spirituality.