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Vesna Pirec MD, PhD

Board Certified Psychiatrist, Chief Medical Officer


Dr. Vesna Pirec has extensive experience with behavioral health issues specific to reproductive cycles in women, including perinatal mental health and postpartum depression, anxiety and psychosis.

Dr. Pirec received her Medical Degree at the University of Belgrade and her PhD in Pharmacology at the University of Illinois in Chicago, Department of Pharmacology.

She is the author of several textbook chapters and articles, and is a member of NASPOG (North American Society for Psychosocial Obstetrics and Gynecology) serving as Elected Board Member en Large, the Marce Sociéty for Perinatal Mental Health, Fellow Member of the American Psychiatric Association (APA), and the Illinois Psychiatric Society.  She speaks several languages, including Spanish.

Prior to joining the staff at Insight, Dr. Pirec was the Program Director of Women’s Mental Health in the Department of Psychiatry at the University of Illinois at Chicago.

Steven Prinz, MD

Medical Director of Eating Disorder Services


Steven Prinz, MD, is a board certified psychiatrist and the Medical Director of Eating Disorder Services at Insight. Dr. Prinz works with Insight’s multidisciplinary treatment team to deliver direct psychiatric care and medication management. In his role at Insight, Dr. Prinz brings extensive expertise in the treatment of serious behavioral health conditions including eating disorders, anxiety, depression, self-injury and substance use disorders. Prior to joining Insight’s medical team, Dr. Prinz served as Medical Director of the Eating Disorder Program and Anxiety Disorder Program at Linden Oaks Hospital at Edward in Naperville, IL. As Director of the Eating Disorder Program for over 22 years, he provided leadership to a multidisciplinary medical treatment team and oversight for inpatient and outpatient levels of care, including Arabella House, a residential care center for eating disorder patients. Dr. Prinz also provided direct psychiatric care and medical management to adult and adolescent patients at Linden Oaks. Since 1994, he has delivered psychiatric care to patients and families struggling with behavioral health concerns in his private practice, Genesis Clinical Services.

Dr. Prinz is a dedicated advocate for behavioral health awareness and education among professionals and consumers alike. He is committed to educating the next generation of physicians in Chicago, providing education and supervision to medical students at the University of Illinois at Chicago Medical Center and the Loyola Stritch School of Medicine. He is also a coauthor of The Anxious Brain (W. W. Norton & Co., 2007), a clinical guide describing brain structure and function and neurotransmitter activity in an effort to help psychotherapists better understand, diagnose and effectively treat anxiety disorders. Additionally, Dr. Prinz has held several leadership designations within the National Association of Anorexia Nervosa and Associated Disorders (ANAD). He currently provides organizational leadership and oversight as a Regional Board Member, and previously served as Vice President and President of the Scientific Committee for ANAD. Dr. Prinz is also a member of the Academy for Eating Disorders and a Diplomate of the American Board of Psychiatry and Neurology.

Dr. Prinz earned his undergraduate degree at Loyola University of Chicago and his Doctor of Medicine at the Chicago Medical School. He completed his Residency in Psychiatry at the Loyola Stritch School of Medicine in  Chicago.

Nancy Tyler, MD

Adolescent and Adult Psychiatrist


Dr. Nancy Tyler has extensive experience in mood and anxiety disorders and treatment or eating disorders in adolescents and adults. She has trained and practiced in adult psychiatry, child and adolescent psychiatry and pediatrics.

Dr. Tyler grew up in Long Island, New York and received her Bachelor’s degree from Tufts University.  She earned her MD from SUNY in Buffalo, New York, completed her pediatric residency at Columbia-Presbyterian Medical Center in New York, her psychiatry residency at Beth Israel Medical Center in New York, and her Child & Adolescent Psychiatry Fellowship at North Shore University Hospital at NYU.

Before joining Insight, Dr. Tyler was an Attending Psychiatrist at Alexian Brothers Behavioral Health Hospital where she cared for patients in the Eating Disorders and Self Injury recovery programs.  Her broad experience in a variety of settings provides a solid foundation for delivering compassionate treatment to patients at all levels of care.  Additionally, Dr. Tyler is conversant in Spanish.

Toya Roberson-Moore, MD

Child and Adolescent Psychiatrist

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Toya Roberson-Moore, MD is a staff Child and Adolescent Psychiatrist for Insight Behavioral Health Centers. Board certified in General Psychiatry and Neurology, she believes in a holistic and integrative approach to the promotion of wellness in adolescents and families while addressing treatment of a variety of mental health concerns. Her clinical interests include treatment of eating disorders and anxiety disorders in the pediatric population. She is also committed to educating future clinicians as evidenced by her role in the co-creation of an internet based pediatric anxiety learning module, a guide for medical students in the diagnosis and treatment of Anxiety Disorders.

She received her bachelor’s degree from the University of Michigan and Doctor of Medicine from Wayne State University. She completed both her Adult Psychiatry Residency and Child and Adolescent Psychiatry Fellowship at the University of Illinois at Chicago.

Dr. Roberson-Moore distinguished herself as Chief Resident during her second year of Fellowship. She has a broad clinical base, with training in Cognitive Behavioral Therapy, Psychodynamic Therapy, Dialectical Behavioral Therapy, Family Therapy, Play Therapy and Parent Management Training. Dr. Roberson-Moore also has extensive training in working with traumatized children and adolescents. She is also deeply involved with her communities as a dancer, volunteer, and mentor.

Dr. Roberson-Moore holds an academic appointment as Clinical Assistant Professor in the Department of Psychiatry at the University of Illinois at Chicago School of Medicine. Dr. Roberson-Moore is a diplomat of the American Board of Psychiatry and Neurology. Dr. Roberson-Moore holds memberships in the American Academy of Child and Adolescent Psychiatry (AACAP), Illinois Psychiatric Society, and Illinois Council of Child and Adolescent Psychiatry.

Lisa Oldson, MD

Medical Director of Adult CORE


Lisa Oldson, MD is an experienced physician Board certified in both Internal Medicine and Obesity Medicine, serves as Medical Director of the Adult CORE program at Chicago-based Insight Behavioral Health Centers.

In her role at Insight, Dr. Oldson oversees the delivery of medical support and care for male and female adults (ages 18 and older) participating in obesity treatment and prevention programming.  She is passionate about helping individuals reach and maintain a healthy weight, and her unique experience fusing expertise in General Internal Medicine and Obesity Medicine helps her to effectively support patients throughout their journey.

Prior to joining Insight’s weight management programming, Dr. Oldson served as an Internal Medicine physician at Northwestern Medical Group (formerly Northwestern Memorial Physicians Group), a leading multi-specialty physician organization in the Chicagoland area. Additionally, Dr. Oldson is committed to training the next generation of physicians and has been a Clinical Instructor at Northwestern University’s prestigious Feinberg School of Medicine since 1998.

Dr. Oldson began her career at Rush Medical College in Chicago, Illinois, where she earned her medical degree and completed her residency. She served as Chief Medical Resident, Internal Medicine and was the recipient of several honors related to her clinical skill and leadership acumen.

“As an Obesity Medicine physician coming from a Primary Care background, I understand the impact of obesity on health as well as on self-esteem, employment, relationships, mood and productivity. Every day, we make a myriad of decisions about food, movement and lifestyle that impact our weight. Insight’s compassionate multidisciplinary treatment team educates and guides individuals as they navigate these decisions for themselves and their families. I’m delighted to join this comprehensive group of dedicated providers.”

– Lisa Oldson, MD

Lynn Gettleman Chehab, MD, MPH

Medical Director of AP CORE


Lynn Gettleman Chehab, MD, MPH is a Board certified, fellowship-trained pediatrician and serves as Medical Director of the Comprehensive Overeating Recovery Effort program for adolescents (AP CORE) at Chicago-based Insight Behavioral Health Centers. In her role at Insight, Dr. Chehab oversees the delivery of medically-supported obesity prevention and recovery programming for male and female adolescents (ages 12 through 17).

In addition to her work with adolescent patients in Insight’s evidence-based weight management programming, Dr. Chehab is a pediatrician at NorthShore University Health Systems and serves as a staff physician at the School-Based Health Center at Evanston Township High School. She first became interested in obesity prevention and treatment as a medical student at Stanford University, where she studied how to target low-income women for cardiovascular disease prevention. After finishing her pediatric training in San Francisco and New York, she completed a public health fellowship at the Columbia University College of Physicians and Surgeons and the Mailman School of Public Health in New York City, obtaining a Master’s degree in Public Health with a concentration in community-based pediatric obesity prevention.  While at Columbia, Dr. Chehab created a program to teach pediatric residents at Harlem Hospital how to screen for and treat obesity using simple messages. She also evaluated “Energy Up,” one of the first school-based obesity programs to focus on self-esteem and emotional eating as an important component in obesity treatment. The results of the evaluation were published in the Journal of Adolescent Medicine, and forever changed how Dr. Chehab approached obesity treatment.  Over the past 8 years, in collaboration with staff at the ETHS health center, Dr. Chehab created “6 to Success,” a clinic-based obesity program that combines simple messages with social work support to help adolescents achieve better weight management.

Heather Fritz, DO

Primary Care Physician

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Dr. Heather Fritz is a Primary Care Physician for Insight Behavioral Health Center’s Adult Residential program. She earned her Medical Degree at Midwestern University and completed her Family Medicine Residency at Lutheran General Hospital.

Dr. Fritz is also the Assistant Attending in the Department of Family Medicine at Mercy Hospital and Medical Center in Chicago. She is deeply involved in the schools in her community through her work at two high school based health clinics.

Dr. Fritz is Board Certified in both Family Medicine and Obesity Medicine. Dr. Fritz also holds a membership in the American Society of Bariatric Physicians.