Greg Thorkelson, M.D.

Dr. Thorkelson completed his adult psychiatry training at Temple University and went on to complete a fellowship in child and adolescent psychiatry at the University of Pittsburgh. He completed additional psychodynamic fellowship training at the Psychoanalytic Center of Philadelphia. At the University of Pittsburgh, he served as Associate Medical Director at the Center for Integrative Medicine, as a staff psychiatrist at the John Merck Center for Autism and Developmental Disorders, and as a psychiatrist with the Visceral Inflammation and Pain (VIP) Center based in the Department of Gastroenterology, Hepatology, and Nutrition.

Dr. Thorkelson has completed additional clinical training in Mindfulness-Based Stress Reduction (MBSR) with Jon Kabat-Zinn, PhD, and Saki Santorelli, EdD. He has advanced training and clinical experience with both Eye Movement Desensitization and Reprocessing (EMDR) and hypnotherapy, and studied advanced nutrient therapies under Dr. William Walsh. Additionally, he completed foundational coursework in Functional Medicine, training alongside staffs from the Cleveland Clinic Center for Functional Medicine.

He has written multiple book chapters, co-authored nearly two-dozen publications, led workshops for Fortune 500 companies, and provided expert opinion for wide ranging media outlets from NBC and to Men’s Health Magazine. He is also a founding member of the Center for Mindfulness and Consciousness Studies at the University of Pittsburgh where he continues to teach residents, fellows, and medical students.

Currently, he is the Medical Director of Behavioral Health at The Children's Institute in Pittsburgh. Dr. Thorkelson is also the founder of The Nexus Group, where he practices integrative psychiatry with adults and children, focusing particularly on the interface between physical and mental health.

Dr. Thorkelson is an intelligent and caring doctor that has been providing services to my child for some time. We have seen great results, and Dr. Thorkelson’s education and experience has been extremely helpful to us throughout the process of working through GAD and MDD issues. He is highly recommended.
— Lauren S.



Mary Beth Rucki,


The Nexus Group, PC is very excited to welcome Mary Beth Rucki to the practice starting in October of 2019!

Dr. Rucki completed her Doctorate in Nursing Practice at Robert Morris University with a specialty in psychiatric mental health. Dr. Rucki brings over 30 years of experience in behavioral health including with clinical work at The Children's Hospital of Pittsburgh, Western Psychiatric Institute and Clinic, and The Allegheny Health System.

At The University of Pittsburgh, she provided rigorous care for adolescents with mood disorders at the internationally recognized Services for Teens at Risk (STAR) Clinic. With the adult mood disorders program at The University of Pittsburgh she provided supervision and direction to dozens of direct care and nursing staff.

In addition to her extensive background in medication management, Dr. Rucki is certified in Cognitive Behavioral Therapy (CBT) through Case Western Reserve University and has worked with thousands of patients since completing her certification in 1994.