Faculty teaching student information on whiteboard

Core faculty

*2020/21 Potential Research Mentors

Jason I. Chen, Ph.D. in Clinical Psychology from the University of South Florida. Dr. Chen is in the Department of Psychiatry at OHSU and the VA Center to Improve Veteran Involvement in Care, located within the VA Portland Health Care System. He is currently a Trans-NIH-funded (NIMH Track) K12 scholar in Emergency Care Research. His research interests include suicide prevention for high risk populations, with a focus on military veterans, community-based approaches, and help-seeking processes. Clinically, Dr. Chen provides supervision on suicide-specific interventions and adapting evidence-based psychotherapies to acute care and non-traditional settings.

Joshua L Clark, Ph.D. in Clinical Psychology, American University and postdoctoral fellowship in Polytrauma at VA Portland. Dr. Clark's expertise lies in the assessment and treatment of survivors of complex trauma with both psychological and medical sequelae.  He is a neuropsychologist at VA Portland and provides psychotherapy through a private practice in the community. 

Nathan F. Dieckmann, Ph.D. in Psychology, University of Oregon. Dr. Dieckmann leads the Statistics Core in the School of Nursing. Areas of statistical expertise include structural equation modeling, longitudinal modeling, and psychometrics. Dr. Dieckmann also conducts basic and applied research in the decision sciences and risk communication. His current work is focused on how people understand and use uncertainty in a range of decision contexts. Other areas of interest include examining lay and expert perceptions of conflicting scientific information and trust in science more generally.

Danny C. Duke, Ph.D. in Clinical Psychology, University of Florida. Dr. Duke has notable expertise (and research interests) in optimizing empirically supported treatment for youth anxiety, obsessive-compulsive disorder, and PTSD, through the Institute on Developmental Disabilities (IDD), Anxiety Treatment Clinic. He also has specialized expertise in the use habit reversal treatment (HRT) to address trichotillomania, tic/Tourette disorders (CBIT), and the body focused repetitive disorders. He holds a degree concentration in Pediatric Psychology, with clinical and research interests in improving youth and family adjustment to chronic health conditions, and optimizing the transition from pediatric to adult healthcare settings and health condition management (self-care), with particular interests in children and adolescents with type 1 diabetes, and their families.

Susanne W. Duvall, Ph.D. in Clinical Psychology, University of New Mexico. Dr. Duvall is the Assistant Director of Clinical Training. Her expertise lies in neuropsychological evaluation and assessment of individuals with autism spectrum disorder. Research interests include development of executive function and neurocognitive outcomes in many medically complicated populations (premature birth, childhood cancer and brain tumors and autism spectrum disorders).

Sarah W. Feldstein Ewing, Ph.D. in Clinical Psychology, University of New Mexico. Dr. Feldstein Ewing is the Director of Clinical Training. She is a licensed clinical child psychologist with over a decade of experience utilizing a variety of evidence-based approaches to prevent and intervene with adolescent health risk behavior, including alcohol use, cannabis use, and HIV/AIDS risk behavior. At this time, her lab has enrolled over 1000 unique youth within large-scale clinical trials to evaluate the developmental fit and treatment outcomes for motivational interviewing, behavioral skills training, cognitive behavioral approaches, mindfulness and contingency management. She has published widely regarding the developmental fit, neurocognitive mechanisms, gender differences, and cross-cultural adaptation of these prevention and intervention approaches for this developmental stage. Read more about Dr. Feldstein Ewing's Translational Research of Adolescent Change Lab

Alice Graham, Ph.D. in Clinical Psychology from University of Oregon. Dr. Graham's research focuses on how the early environment influences developing brain systems and risk for mental health disorders. Her work employs MRI beginning in the neonatal period to characterize the developing brain. Her clinical interests lie in employing intervention to prevent or ameliorate effects of stress exposure on children and families. Reach more about Dr. Graham's research

David W. Greaves, Ph.D., received his Clinical Psychology degree from Brigham Young University. Dr. Greaves has worked primarily in administrative roles for several years, but also provides clinical services in health psychology settings at the VA Portland Health Care System.  He is the Clinical Director of the Whole Health Service at the facility, and is the past Chief of Psychology.

Amy Holley, Ph.D. in Clinical Child Psychology, Case Western Reserve University. Dr. Holley's expertise lies in the assessment and treatment of youth with chronic pain and their families. Research interests include how psychopathology and sleep disturbances influence pain-related disability in youth experiencing acute or chronic pain and the identification of mechanisms underlying the development of chronic pain. Dr. Holley is part of the Advancing Research in Pediatric Pain lab.

Marilyn Huckans, Ph.D.* in Clinical Psychology, George Mason University. Dr. Huckans serves as the Director of Training for Psychology at the VAPORHCS. As a neuropsychologist at the VAPORHCS, she provides neuropsychological assessment, cognitive rehabilitation, and consultation services. Her translational research program integrates human, animal, and in vitro experiments to examine the neuropsychiatric effects of medical, psychiatric and substance use disorders, with a particular focus on the development and discovery of novel treatments for these conditions. Her VA and NIH funded projects have utilized neuropsychological assessment, neuroimaging, and immunological techniques to evaluate clinical outcomes in the context of traumatic brain injury (TBI), posttraumatic stress disorder (PTSD), mild cognitive impairment (MCI), depression, hepatitis C, HIV, alcohol abuse and methamphetamine dependence, with projects primarily aimed at the development of immunotherapies for addiction and cognitive rehabilitation interventions for mild cognitive impairments.

Jeni Johnstone, Ph.D. in Psychology, University of Otago, New Zealand; Post-Graduate Diploma, Clinical Psychology, University of Canterbury, New Zealand; MA in Counseling Psychology, Santa Clara University, CA. As a clinician-scientist, Dr. Johnstone conducts clinical trials in integrative treatments (e.g., mindfulness and micronutrient supplementation) for ADHD, mood and behavioral issues in adults and children. She works with patients ranging in age from children through adults, and provides therapy to families in a Family Therapy Clinic.

Sarah Karalunas, Ph.D.* in Clinical Psychology, Pennsylvania State University. Dr. Karalunas' research takes a multi-method approach to characterizing the basic psychological and neurophysiological processes contributing to ADHD and other neurodevelopmental disorders. Current research focuses on understanding individual differences in cognition and emotion using behavioral, neuropsychological, and electroencephalogram approaches.

Amy Kobus, Ph.D. in Counseling Psychology, University of Iowa. Dr. Kobus has a general clinical practice and provides both counseling and assessment services to adults, adolescents, couples and families. She has specialized training in health psychology, chronic pain management and primary care psychology. She has considerable experience with young adults, psychological aspects of medical illness, and cultural issues. Dr. Kobus’ previous research has focused on chronic pain, HIV and cervical cancer prevention with the Asian community using mixed-methods and community-based participatory research. Her current research interests are in chronic pain and opioid treatment, behavioral health integration in primary care, and health disparities and community-based research.

Jennifer Loftis, Ph.D.* in Behavioral Neuroscience and postdoctoral fellowship in Molecular Microbiology and Immunology, Oregon Health & Science University; MA in Clinical Psychology, Fairleigh Dickinson University, New Jersey. Dr. Loftis possesses a unique set of experiences and resources that are ideal for bridging the interrelated disciplines of neuroscience, immunology and molecular biology to tackle mental health disorders from a comprehensive perspective. Her translational research program is focused on investigating the psychoneuroimmunological mechanisms contributing to substance use disorders and neuropsychological impairments (e.g., cognitive deficits and mood disorders) and how immunotherapeutic strategies can be used to treat these conditions. Read more about the Psychoneuroimmunology Research Team and the Methamphetamine Abuse Research Center.

Travis I. Lovejoy, Ph.D.* in Clinical Psychology, Ohio University. Dr. Lovejoy's clinical expertise is in health psychology, behavioral medicine, and substance use disorders. His research interests include optimizing pain management in patients with co-occurring chronic pain, mental health, and substance use disorders, as well as HIV prevention in traditionally underserved populations.

Kristen Mackiewicz Seghete, Ph.D.* in Clinical Psychology from the University of Colorado Boulder. Dr. Mackiewicz Seghete's clinical expertise is in pediatric neuropsychological evaluations and working with children and families who have experienced maltreatment and interpersonal violence. Her research interests include alterations to cognitive and affective brain processes across the lifespan in individuals with a history of childhood maltreatment and neurobiological mechanisms of the intergenerational transmission of the effects of childhood maltreatment.

Leeza Maron, Ph.D. in Clinical Psychology (specialization in Neuropsychology), University of Florida. As Director of the Adult Neuropsychology Clinic, Dr. Maron provides clinical and forensic neuropsychological evaluations to a broad range of patients with suspected neurocognitive disorders. Research interests involve the development and implementation of novel neuropsychological paradigms to study executive dysfunction and attentional failures in those with ADHD and other psychiatric disorders.

Suzanne H. Mitchell Ph.D.* in Biopsychology, State University of New York –Stony Brook. Dr. Mitchell's research uses neuroeconomic principles to understand choice behavior in healthy normal and patients behavior. Studies include the genetic and neurobiological bases and consequences of impulsive and risky behavior. Read more about Dr. Mitchell's Translational Neuroeconomics Lab.

Benjamin Morasco, Ph.D.*, received his Clinical Psychology degree from Saint Louis University. Dr. Morasco provides clinical services in the specialty substance abuse treatment program at the VA Portland Health Care System, with a focus on treating non-substance-related addictive behaviors. His research interests are on improving the safety and effectiveness of pain management interventions, with a specialty interest in treating patients with co-occurring psychological and substance use disorders.

Bonnie J. Nagel, Ph.D. in Clinical Psychology, with emphasis in Neuropsychology, University of Memphis. Dr. Nagel's clinical expertise lies in pediatric neuropsychological evaluation. Research interests include exploring typical and pathological adolescent brain and cognitive development using structural and functional neuroimaging and neuropsychological assessment techniques. Read more about Dr. Nagel's Developmental Brain Imagining Lab.

Joel Nigg, Ph.D.* in Clinical Psychology from University of California, Berkeley. Dr. Nigg's research focuses on the underlying mechanisms and causes in attention deficit hyperactivity disorder (ADHD) across the lifespan. The primary focus is on cognitive and neuropsychological mechanisms. However, studies of genetics, family dynamics, personality and temperament, environmental toxins, and neuroimaging of ADHD are also ongoing. Read more about Dr. Nigg's ADHD and Attention Research Lab.

Maya O'Neil, Ph.D.* in Clinical Psychology from University of Oregon. Dr. O'Neil received her doctorate from the University of Oregon and completed her internship at VAPORHCS. She is an AHRQ-funded PCOR K Scholar at OHSU. She provides supervision related to assessment and neuropsychological research and clinical work and conducts neuropsychological assessments, cognitive rehabilitation, and PTSD treatment. Her clinical interests include neuropsychological assessment and treatment of comorbid PTSD and TBI. Her research interests focus on statistics and systematic review methodologies, cultural competence assessment and training, and the psychological and cognitive effects of trauma, blast exposure, and TBI.

Sara Walker, Ph.D. in Clinical Psychology, University of California, Santa Barbara, and postdoctoral fellowship in Clinical Neuropsychology from the University of Michigan. Dr. Walker provides clinical services to adults referred for comprehensive neuropsychological evaluations in the Adult Outpatient Psychiatry Clinic at OHSU. Research interests and activities are related to cognitive functioning and quality of life among individuals with cancer.  Dr. Walker is also active in providing disaster mental health services and psychological first aid in the region.

Anna Wilson, Ph.D. in Clinical Psychology from University of Washington. Dr. Wilson conducts research on functional outcomes in adolescents with chronic pain with a focus on developing prevention and treatment programs to reduce pain and disability. She also provides behavioral assessment and treatment to children and adolescents through the Pediatric Pain Management and Coping Clinics. Read more about Dr. Wilson's Advancing Research in Pediatric Pain Lab.

Tyler Duffield, Ph.D. - Specializes in treating children impacted by mild traumatic brain injury or neurologic disease, and their families.

Thomas Kern, Ph.D. - Specializes in helping patients manage chronic pain and other chronic conditions.

Emily Olsen, Ph.D. - Provides neuropsychological assessment, consultation, and treatment for youth with developmental and medical complexity.

Kim Reynolds, Ph.D. –Provides psychological assessment and treatment to children with developmental disabilities and chronic medical conditions.

Kimberly Spiro, Ph.D. - Co-directs the Novel Interventions in Children's Healthcare, which assists youth with chronic medical conditions and their families.

Jason Steward, Ph.D. - Provides psychological assessment and treatment to trauma survivors within populations of sexual assault, combat, terrorism, maltreatment, and sudden bereavement.

David Wagner, Ph.D. - Provides behavioral and family-based therapies for children and families and supervises within the NICH program.