Psychology Internship Faculty
Brant VanOrman, PsyD, is the Training Director for the pre-doctoral psychology internship at Pine Rest. He graduated from Wheaton College after completing his internship with Pine Rest. He then conducted assessment and therapy at the Grand Haven clinic for two years before transferring in 2002 to the Psychological Consultation Center on Pine Rest’s main campus. He is an Adjunct Assistant Professor at Michigan State University’s College of Human Medicine. His current outpatient work is largely related to psychological assessment and consultation. He was named Training Director for the internship beginning in 2007. He facilitates the integration of faith, science and practice through the Case Conference Seminar. He supervises the Autism Spectrum Disorder rotation.
Mark DeVries, PhD, is a licensed psychologist who has provided psychological and neuropsychological assessment services since 1992 in a number of settings in Grand Rapids including the psychiatric medical unit, Pine Rest’s Psychological Consultation Center, Pine Rest’s inpatient and outpatient programs, and Hope Network Rehabilitation Services. He supervises the neuropsychological assessment rotation. He completed a PhD in clinical psychology at Fuller Theological Seminary’s Graduate School of Psychology in 1992. He is a member of the National Academy of Neuropsychology (NAN). He currently provides a number of assessment services for adults and older adults, including dementia assessments, ADHD assessments, and clinical psychology assessments.
Sera Gruszka, PhD, is the Assistant Training Director for the pre-doctoral psychology internship at Pine Rest. She graduated from Ball State University in 2011 after completing her internship with Pine Rest. Her post-doctoral work included outpatient therapy in a traditional mental health setting and in a primary care setting. Additionally, she completed one year of a post-doctoral fellowship in neuropsychology. She currently works at the Campus Clinic on Pine Rest’s main campus and provides outpatient therapy to individuals, couples, and families. Her areas of clinical interest include anxiety disorders, OCD, chronic pain, older adult concerns, and marital and family issues. She is a supervisor for Pine Rest’s Psychiatry Residency Program. She was named Assistant Training Director for the internship beginning in 2014. She also supervises the Caring Communities rotation. Dr. Gruszka is an Adjunct Assistant Professor at Michigan State University’s College of Human Medicine.
Scott Halstead, PhD, is a supervisor for the Van Andel inpatient rotation and neuropsychological testing. Dr. Halstead received his degree from Fuller Theological Seminary in 1992, served as a psychologist with the U.S. Air Force from 1991 to 2003, and completed a two-year neuropsychology fellowship at Brown University in 2000. Joining Pine Rest in 2003, he is the Corporate Director of Pine Rest’s Professional Practice Group. He also provides outpatient and inpatient neuropsychological evaluations. Dr. Halstead specializes in working with older adults with memory disorders, and presents to interns on this and other assessment issues.
Gregory Mallis, PsyD, is the supervisor for the Christian Counseling Center outpatient therapy rotation. Dr. Mallis received his undergraduate degree from the University of California, San Diego, and his doctoral degree from the University of Indianapolis in 2012. He joined Pine Rest in 2013. Dr. Mallis has previously worked in settings that include university counseling centers, completing his internship at Purdue University Counseling and Psychological Services. Dr. Mallis’s current clinical areas of interest include working with young adults and adults with anxiety disorders, mood disorders, identity and phase of life issues, relationship issues and couples counseling, compulsive sexual behaviors, men’s issues, and sexuality concerns. He supervises one of the therapy placements at the Southwest Clinic.
Daniel Post, PsyD, is a licensed psychologist who has practiced at Pine Rest Christian Mental Health Services since 2010. He is the lead forensic psychologist within the Psychological Consultation Center at Pine Rest. Dr. Post completed his undergraduate degree at Calvin College and doctoral degree at Wheaton College. His work experience includes inpatient, outpatient, and forensic assessment and treatment across a diverse population. He provides pre- and post-doctoral psychological supervision and is in charge of the residential testing rotation. Dr. Post has been an adjunct instructor with Michigan State University since 2016, providing forensic lectures and supervision to second and third year psychiatric residents. Dr. Post’s current clinical areas of interest include specialty assessment services, supervision, and the treatment of anxiety, mood, and behavioral disorders in children and adults. Dr. Post is a member of the American Psychological Association. He supervises the Child and Adolescent Hospital rotation.
Bruce Retterath, PhD, is a licensed psychologist who has practiced at Pine Rest Christian Mental Health Services since 1993. He is the manager of the Psychological Consultation Center at Pine Rest. Dr. Retterath completed his undergraduate and doctoral degree at the University of North Dakota. His prior work experience includes inpatient, outpatient and residential settings. Dr. Retterath’s current clinical areas of interest include the assessment and treatment of ADHD, anxiety disorders and mood disorders, diagnostic/personality evaluations, pre-surgical evaluations, learning disability evaluations, and management consultations. Dr. Retterath is a member of the Anxiety Disorders Association of American, American Association of Christian Counselors, and Michigan Psychological Association.
Christina Russell, PhD, LP, is a licensed psychologist who has provided psychological assessment and therapeutic services for toddlers, adolescents, young adults, and families across multiple settings including school districts, early intervention, and clinical settings. She received her undergraduate degree in psychology from Michigan State University and completed her PhD in school psychology at Indiana University. Dr. Russell initially practiced as a school psychologist in Houston, TX. She then provided early intervention and clinical services in Denver, CO. Dr. Russell has a special interest in the assessment of children with autism spectrum disorders and other developmental disabilities, behavior consultation, parent training and advocacy regrading special education. She currently supervises the Autism Spectrum Disorder assessment rotation at the Psychological Consultation Center.
Lisa Schirmer, LP, is a licensed psychologist who has over 30 years of experience working with diverse populations in a variety of clinical settings including outpatient clinics, employee assistance programs, hospitals, intensive outpatient programs and partial hospital programs. She received her M.Ed. in Counseling from McGill University in Montreal, Quebec and earned a Ph.D. in Counseling Psychology from Michigan State University.
Dr. Schirmer believes that empowering relationships are central to healing and recovery. Her clinical orientation is rooted in cognitive behavior theory and therapies. Dr. Schirmer’s areas of interest include working with clients experiencing life transitions, work stress and interpersonal conflict; as well as those struggling with depression, anxiety, living with a chronic mental illness, suicidality, and co-occurring mental health and substance use disorders.
Dr. Schirmer has published and presented on topics related to adult attachment style and work stress, relationship based care, substance use and co-occurring disorders, group therapy, brief interventions and resilience. She supervises one of the therapy placements at the Southwest Clinic.
Lisa Vroman Stokes, PhD, supervises one of the therapy placements at the Forest Hills Clinic. She completed her undergraduate degree at Michigan State University and remained there for her graduate training where she earned her doctoral degree in clinical psychology in 2015. She joined Pine Rest in 2019. Dr. Vroman Stokes currently serves as the Child & Adolescent Project Coordinator and is a member of the DBT-Informed team. She works primarily with children, adolescents, and young adults. Dr. Vroman Stokes places a strong emphasis on the importance of creating a warm, collaborative therapeutic relationship and recognizes the need to adopt a flexible and creative approach to treatment when working with children and families. Her areas of clinical interest include treatment of ADHD, anxiety and mood disorders, childhood behavior problems, phase of life concerns, and relational/family conflict.
Mark Eastburg, PhD: President / Chief Executive Officer
Bob Nykamp: Vice President / Chief Operating Officer
Scott Halstead, PhD: Corporate Director, Professional Practice Group
Harmony Gould: Corporate Director, Hospital Based Services
Gary Burkhart: Chair of Psychology Department