Allison Cheng, MD

Dr. Thomas O’Brien holds a Bachelor of Science degree from the University of Wisconsin–Madison and earned his medical degree from Midwestern University Chicago College of Osteopathic Medicine. He completed his psychiatry residency at Loyola University Medical Center. Dr. O’Brien has experience practicing across outpatient, PHP, IOP, and inpatient settings.

He strives to create a supportive environment where patients feel heard, respected, and understood. His approach emphasizes a holistic, whole-person method to healing, guided by the patient’s own goals and values. Dr. O’Brien integrates psychotherapy with medication management, drawing on his background in psychodynamic psychopharmacology and acceptance and commitment therapy.

Dr. O’Brien focuses on understanding each patient as a whole to create individualized treatment plans. This begins with a comprehensive history during the initial session to identify biopsychosocial factors. Treatment is then tailored to align with the patient’s unique goals and values, promoting meaningful progress.

Dr. Mattern is board certified in Adult psychiatry. Her approach to mental health is integrative, with the utilization of complementary and alternative treatments such as yoga, lifestyle changes, and nutritional interventions in addition to traditional medication management and therapy. Dr. Mattern prefers to focus on the overall health and well-being of an individual, rather than just treating symptoms.

Dr. Mattern’s practice focuses on medication management along with elements of therapy from different modalities, such as supportive and cognitive behavioral therapy that are patient-tailored.  Dr. Mattern understands the importance of psychotherapy and may ask to bring in a therapist into your treatment team to provide the best care and outcome. Her clinical interests include depression, bipolar disorder, anxiety disorders, post-traumatic stress disorder, panic disorder, OCD, and ADHD.

After completing her undergraduate degree in Biology at Ohio Northern University, Dr. Mattern received her medical degree from Ohio University Heritage College of Osteopathic Medicine. She went on to complete her residency in psychiatry at The Ohio State University Medical Center.  She also completed yoga teacher training and presented nationally at the APA in 2019 regarding the benefits of yoga for depression.  Dr. Mattern is a member of the American Psychiatric Association, Ohio Psychiatric Physician’s Association, and Psychiatry Society of Central Ohio.

Dr. Mattern is board certified in Adult psychiatry.  Her approach to mental health is integrative, with utilization of complementary and alternative treatments such as yoga, lifestyle changes, and nutritional interventions in addition to traditional medication management and therapy. Dr. Mattern prefers to focus on the overall health and well-being of an individual, rather than just treating symptoms.  Dr. Mattern’s practice focuses on medication management along with elements of therapy.

Denise White, PMHNP, has worked in the mental health field for over 30 years following the completion of her Bachelor’s degree in Psychology from Suffolk University in Boston. She began her career as a mental health technician in a geriatric residential program and later pursued additional education in nursing, earning an Associate Degree in Nursing from Quincy College, a Bachelor’s Degree in Nursing from South University, and a Master’s in Nursing from Eastern Kentucky University. Over the years, she has held diverse roles in adult and children’s case management, residential and intensive outpatient programs, inpatient psychiatric care, and crisis stabilization. Denise has provided care in both inpatient and outpatient settings as well as through hospital consult services across the country.

Denise prides herself on her ability to empathize with her patients and meet them exactly where they are in their journey. She believes that trust is the foundation of the therapeutic relationship and works diligently to create a supportive, nonjudgmental environment where patients feel safe, heard, and respected.

In the initial evaluation, Denise focuses on gathering comprehensive information to form a complete understanding of each patient’s unique background and needs. From there, she develops an individualized treatment plan that aligns with the patient’s prioritized goals. Each session begins from that foundation, allowing her to support patients at their own pace as trust deepens and progress unfolds.

Dr. Steve Paschos is a board-certified Psychiatrist at Talkiatry. He attended Loyola University Chicago on the Lake Shore campus, completing a bachelor's degree in science and a Degree in Classical Studies. He then attended Medical School at Rush Medical College in Chicago and completed a 5-year combined Internal Medicine & Psychiatry residency in 2011. Dr. Paschos subsequently completed a 1-year fellowship in Geriatric Medicine at Rush University Medical Center. He has spent the last 12 years fulfilling his passion for integrating Internal Medicine & Psychiatry, working with a diverse range of patients suffering from severe mental illnesses. ‍Dr. Paschos' years of experience have included working at Cook County Health Services � Cermak Health Services at Cook County Department of Corrections with an extremely diverse patient population with varying psychiatric illnesses. He has also worked as an inpatient psychiatric hospitalist and as the director of the Intensive Care Unit at Chicago Behavioral Hospital in Illinois. Dr. Paschos also acted as a medical director of an IOP and established an outpatient psychiatric practice in conjunction with the Intensive Outpatient Program. He has had the opportunity and privilege of treating individuals who suffer from various diagnoses, especially challenging patients who have suffered from integrated or Med-Psych concerns involving primary mood disorders, Bipolar Affective disorders, prior trauma, severe medical problems/diagnoses along with concurrent personality pathology. ‍Dr. Paschos utilizes supportive psychotherapy, brief cognitive behavioral therapy, and at times psychodynamic therapy to address his patients' current complaints and to identify the locus of their symptoms. He believes in utilizing an all-encompassed approach using mindfulness and various psychotherapies along with comprehensive medication management. To quote Hippocrates "Where there is love for the art of medicine there is a love of humanity.”

Dr. Ahmed Valdes is a board certified adult psychiatrist and burgeoning Geriatric Psychiatrist. After completing his undergraduate education at Florida State University, he attended medical school at the University of Miami Miller School of Medicine where he graduated with a combined M.D./M.S. in Genomic Medicine. He subsequently completed psychiatry residency at Jackson Health System/University of Miami and further subspecialized with a fellowship in Geriatric Psychiatry. Dr. Valdes has had the opportunity of working with a diverse array of patients including veterans, inmates, the severely mentally ill, geriatric, and cancer patients across three distinct hospital systems. Dr. Valdes has had varied clinical experiences in specialty inpatient psychiatry units (detox, geriatric, mood disorder), emergency psychiatry, consultation liaison psychiatry, psycho-oncology, and outpatient specialty clinics (HIV, dementia, integrative and collaborative care) via telemedicine and face to face interactions .Dr. Valdes has experience working with adults of all ages, particularly those with depression, anxiety, bipolar disorder, substance use disorders, PTSD, and more. Dr. Valdes employs empathic listening, supportive psychotherapy techniques, and a comprehensive and methodological approach to his visits. Given his broad and diverse training experiences, he enjoys problem solving and working collaboratively with patients to navigate their complex issues and jointly focusing on simple solutions to work towards improving their mental health.

Dr. Bardugon is a board-eligible psychiatrist who specializes in the treatment of adults. He has experience in treating patients with various forms of depression and anxiety, bipolar disorder, OCD, ADHD, PTSD, and substance use disorders. He seeks to provide a safe, non-judgmental, gender affirming space for patients as they strive to lead a happier, more contented life. After a pediatrics residency, Dr Bardugon worked for 13 years as a pediatric ER physician. His interest in psychiatry was piqued during this time as he witnessed the emergence of a child and adolescent mental health crisis. While ultimately deciding to focus his efforts on the treatment of adults, Dr Bardugon is keenly aware of the influence of child development and family systems on the behavioral health of adults. Dr Bardugon employs a holistic, multimodal treatment approach. Aiming to treat the whole person, he stresses the importance of nutrition, exercise, and sleep. Dr Bardugon believes an informed patient actively engaged in decision making surrounding treatment has the best chance of effecting lasting change. Believing in the synergistic effect of talk therapy and medication, he incorporates one or more talk therapy techniques including motivational interviewing, cognitive behavioral therapy, and supportive and psychodynamic psychotherapies into most sessions. He often recommends formal participation in some form of talk therapy and is happy to collaborate with other providers.