Dr. Walter Duffy, MD


Dr. DDr. Duffy is the CEO/Owner/Founder of Premier Psychiatric Group, LLC (PPG) and Premier Psychiatric Research Institute, LLC (PPRI), and Premier Psych TMS.  He is Board Certified in Child/Adolescent and  Adult Psychiatry.  He graduated from Vanderbilt University School of Medicine in Nashville, TN and then completed his residency training at Dwight D. Eisenhower Army Medical Center  (DDEAM) in Georgia  and his Child Fellowship in a combined program with DDEAM and the University of Georgia. Originally from Shenandoah, IA,  Dr. Duffy and his wife have been married 30 years and have three sons and two daughters-in-law.

Dr. Duffy performs diagnostic evaluations and provides medication management.  He is committed to bringing patients the best, most up-to-date and comprehensive services available.  In 2011 he began offering transcranial Magnetic Stimulation for treatment-resistant major depressive disorder (TR-MDD) and other illnesses. TMS is a non-invasive, FDA-approved treatment procedure for TR-MDD.  Dr. Duffy  and PPG quickly became national leaders in this treatment.  They have treated over 600 patients, performing more than 10,000 treatment sessions with close to 75% of patients having successful outcomes. (Read more under the "TMS" tab on the Home page.)  Also offered now at PPG is Pharmacogenetics, the testing of a patient’s DNA to help find the most effective medication.  This  new test involves nothing more than using a q-tip to take a swab of the inside of the patient’s cheek.  (Read more about Pharmacogenetics under the "Services" tab on the Home page.)

Dr. Duffy's clinical interests include the majority of diagnoses across the child, adolescent and adult spectrum of disorders. He has extensive experience with ADHD; Asperger's, Autism and other pervasive developmental disorders; behavioral problems; Depression; Bipolar disorder; OCD, PTSD and other anxiety disorders; Eating disorders; traumatic brain injury, Sleep problems; Tourette's and other tic disorders; Alzheimer's;  Schizophrenia and other psychotic disorders; Alcohol abuse; Substance abuse; and others.  Dr. Duffy likes the challenge of correctly diagnosing patients and helping them get better using medication management and other treatments.

Dr. Duffy also enjoys clinical research and thus established PPRI in 2003, again giving patients the widest range of treatments available.  His institute has completed numerous stage 2, 3 and 4 pharmaceutical studies involving  children, adolescents and adults.  PPRI works with central IRBs and has been sought out for the excellent enrollment and cleanliness of data it delivers.  Dr. Duffy’s interest in research began during residency when he was  awarded the Lilly Research Award in Psychiatry.  To read more go to the "Research" tab on the Home page.  

Dr. Duffy engages in forensic work as well as consultation work with a number of companies.  Dr. Duffy and PPG excel in determinining if services/products are ready for patient use and then making them accessible to patients.  He has given numerous local and regional talks in regard to diagnoses and medication management to a variety of professional and lay audiences.


 Kelly Espenshade, MA, LMHP


Kelly graduated from the University of Nebraska – Lincoln with a BA in Psychology. She then attended the University of Northern Iowa and graduated with a MA in Clinical Psychology. She went on to receive her license as a mental health practitioner (LMHP) which she is excited to use both in the research field administering assessments and in the clinical field. Kelly has had experience conducting clinical research trials (pharmaceutical, device, and pharmacogenomics) for over 7 years as she took part in clinical trials during both her undergraduate and graduate programs. She started working at Premier Psychiatric Research Institute as a research coordinator and TMS technician almost three years ago and after two years she was promoted to the position of the Clinical Research Manager. Kelly’s passion includes both research and working clinically with patients providing therapy to children and their families. In her free time she enjoys spending time with family, friends, and her dog Lexi.


 Chaitasi Majmudar, MA


Chaitasi received her master’s degree in Counseling Psychology from the University of Nebraska-Lincoln, in Fall 2014. She has been working with PPRI since then as a Clinical Research Coordinator. During her tenure here, she has worked extensively on several studies spanning a spectrum of mental health indications such as depression, anxiety, ADHD, Bipolar Depression, Tardive Dyskinesia, and Tourette’s. She has worked with people of all age groups, from 6-85 years old, and has vast experience in various psychological assessments and rating scales. Chaitasi is originally from India where she received her bachelor’s degree in Biomedical Engineering, however her intrinsic passion for psychology and mental health prompted her to transition into this field and move to the US. Chaitasi finds clinical research to be very rewarding since she enjoys interacting with patients and learning about their experiences, as well as the analytical components of her job such as data collection, data entry and query resolution


 Katy Boman, RT(R)


Katy Bowan v1Katy graduated from Hastings College with a BA in Biopsychology and Allied Health. She then went on to pursue a Radiological technician degree through Mary Lanning School of Radiological Technology.  Her knowledge of the medical field has helped transition her into the role of a Clinical Research Coordinator here at Premier. 

In her spare time she enjoys spending time with her two daughters Layla and Bianka. She also enjoys spending time with family and friends, attending sporting events and catching up on a good book.


 Gitti Janwatanagool, MD, MS


Gitti JDr. Gitti Janwatanagool is currently a Research Medical Coordinator for Premier Psychiatric Research Institute (PPRI). He graduated from the UMKC School of Medicine in 2012. In 2014, he graduated from the UMKC SOM Department of Biomedical and Health Informatics with a Master of Science degree in Bioinformatics, emphasis in Clinical Research. He has participated in medical residency for Family Medicine at UCONN in Hartford, CT.

While at PPRI, he helps conduct studies in psychopharmacology, medical device testing, and pharmacogenomics assay testing for major depressive disorder. He also participates in medical research paper writing.

A native to the Midwest, he has lived a variety of places including Kansas City, Saint Louis, and now Lincoln, NE. He enjoys playing tennis, swimming, cooking, and IT/computer hardware and programming in his spare time.