Skip to main content

Matthew Koller, MD

Staff Psychiatrist
Languages
English
SPECIALTIES
Anxiety
Bipolar Disorder
Depression
Obsessive-compulsive disorder (OCD)
PTSD/Trauma
Phobias
Postpartum Depression
Geriatric

Education and training

•  University of Texas at Austin, BS

•  University of Texas, San Antonio, MD

•  Baylor College of Medicine, Residency

Get to know

Matthew Koller, MD

Background and credentials

Dr. Matthew Koller is a board-certified adult psychiatrist who completed his undergraduate training at The University of Texas at Austin. He earned his medical degree from The University of Texas Health Science Center at San Antonio and completed his general adult psychiatry residency at Baylor College of Medicine in Houston, TX, where he served as Chief Resident of Education in his final year of training.

Treatment approach

Dr. Koller believes that understanding a patient fully is essential before treatment begins, emphasizing a collaborative and patient-centered approach to care. His practice is primarily focused on medication management, but he also incorporates supportive therapy and other therapeutic modalities as needed. He may recommend including a therapist in the treatment plan to ensure comprehensive, well-rounded care. He has experience treating a wide range of mental health conditions, including depression, anxiety, insomnia, personality disorders, bipolar disorder, PTSD, and psychotic disorders.

What you can expect in a first visit

During the first visit, patients can expect a thorough and individualized psychiatric evaluation, where Dr. Koller takes the time to understand their symptoms, history, and treatment goals. He prioritizes open communication and shared decision-making, working closely with patients to develop personalized treatment plans. While medication management is the foundation of his approach, he remains flexible and adaptive, incorporating therapy and other interventions as needed to help patients achieve optimal mental health.

Why Talkiatry?

We’re a virtual mental health practice that makes it easy to find great care. We combine quality and convenience to help you thrive—faster. Our providers, like this one, are highly trained experts who specialize in medication management and collaborate with you on a treatment plan that fits your needs and comfort level.

Get matched with a clinician like this one

Ready to book your first appointment? Take our 10-minute assessment. We’ll match you with a clinician who meets your needs, has availability, and takes your insurance.

Get started
More Clinicians

Michelle Hornbaker-Park, MD

Staff Psychiatrist

Dr. Michelle Hornbaker-Park is a board-certified General and Child and Adolescent Psychiatrist with over nine years of experience. Her practice focuses on medication management, which is founded not only on evidence-based medicine but also on the understanding that a trusting therapeutic relationship is the cornerstone of behavioral health healing. She incorporates CBT, supportive therapy, and psychoeducation into her medication management appointments and may refer patients for additional psychotherapy to improve outcomes. Dr. Hornbaker-Park received her Bachelor of Science degree from Ursinus College, with a dual major in Biochemistry/Molecular Biology and Neuroscience. After receiving a Health Professions Scholarship from the Army, she obtained her medical degree from Jefferson Medical College. She went on to enter active duty military service and complete General Psychiatry residency training and Child and Adolescent Psychiatry fellowship training at Tripler Army Medical Center before completing active duty service as a staff psychiatrist and 101st Airborne Division psychiatrist at Fort Campbell, KY. There she cared for active duty service members and their families to manage depression, anxiety, trauma, and the unique stressors of military service. She later transitioned to federal civilian service and served as a preceptor for Phase II Physician Assistant trainees and Army Social Work interns, reinforcing a passion for education that carried her to Walter Reed National Military Medical Center (WRNMMC). During her time at WRNMMC, she served in several roles including Deputy Medical Director of Inpatient Psychiatry, core faculty for the National Capital Consortium Psychiatry Residency Program, Associate Program Director, and associate faculty at the Uniform Services University for Health Sciences (USUHS). Prior to transitioning out of federal service to join Talkiatry, she was repeatedly recognized for excellence in academics and mentorship and received multiple teaching awards. This zeal for education and mentorship, as well as humility, personal growth, and learning, translates directly into her philosophy for patient care. She believes a whole-person approach with open, collaborative teamwork is the key to progress.

Hunada Zein Eddin, LPC

Staff Therapist

Hunada Zein-Eddin is a bilingual (English/Arabic) Licensed Professional Counselor (LPC) in Texas and Virginia. She earned her degree in Clinical Mental Health Counseling from Lancaster Bible College in 2022 and completed her residency at Northern Virginia Family Service and Youth For Tomorrow. She specializes in supporting adolescents, young adults, and adults with challenges related to anxiety, depression, ADHD, PTSD, adjustment issues, and mood disorders. Hunada also helps clients navigate stress, grief, workplace relationships, anger, and life transitions. She has experience working with individuals, families, and couples and is certified in Trauma-Focused Cognitive Behavioral Therapy (TF-CBT) as well as ADHD Clinical Services. Her trauma-informed, culturally sensitive approach draws on Attachment Theory, TF-CBT, DBT, Narrative Therapy, Internal Family Systems (IFS), and Polyvagal Theory.

Hunada understands that life often brings challenges that can feel overwhelming. She partners with clients on their journey toward healing, peace, and resilience by creating a safe, supportive, and non-judgmental space. Clients can expect empathy, compassion, and professionalism throughout their care. Her therapeutic style emphasizes collaboration, open communication, and a strong belief that everyone deserves access to high-quality mental health services that foster healing and growth.

Hunada begins therapy by building trust and gaining a thorough understanding of each client’s unique history, concerns, and goals. Initial sessions focus on creating a comprehensive biopsychosocial picture that informs the development of individualized treatment plans aligned with the client’s desired outcomes. Throughout treatment, Hunada ensures clients feel heard, valued, and supported as they work toward achieving their therapeutic goals and long-term emotional well-being.

Christine Reyes, MD

Staff Psychiatrist

Background  and credentials    

Dr. Christine Reyes is a bilingual Spanish-speaking adult psychiatrist with  25 years of experience. She completed her residency in Adult Psychiatry at  Saint Vincent's Hospital and Medical Center in New York City and subsequently  completed a Child Psychiatry fellowship at the University of Pennsylvania in  Philadelphia. Dr. Reyes has extensive experience practicing in outpatient and  community mental health settings.    

Treatment approach    

Dr. Reyes provides compassionate psychiatric care using pharmacotherapy  combined with supportive psychotherapy. She specializes in treating anxiety,  depression, bipolar disorder, post-traumatic stress disorder (PTSD), and  numerous other psychiatric conditions. Additionally, Dr. Reyes emphasizes  nutritional counseling, assisting patients in achieving and maintaining a  healthy weight as part of their overall wellness plan.    

What you can expect in a first visit    

Patients can expect a compassionate and thorough initial assessment aimed  at understanding their psychiatric symptoms, personal health goals, and  lifestyle considerations. Dr. Reyes combines medication evaluation with  supportive psychotherapy and may discuss nutritional guidance as part of a holistic  treatment plan. She prioritizes creating a supportive environment for  bilingual (English/Spanish) patients to openly discuss their mental health  concerns.    

Why Talkiatry?    

We’re a virtual mental health practice that makes it easy to find great  care. We combine quality and convenience to help you thrive—faster. Our  providers, like this one, are highly trained experts who specialize in  medication management and collaborate with you on a treatment plan that fits  your needs and comfort level.

Ann Landowne, MD

Staff Psychiatrist

Dr. Ann Landowne is Board Certified in Adult, Adolescent, and Child Psychiatry. She has over thirty-five years of experience helping people of all ages cope with a wide range of problems. Dr. Landowne received her medical and psychiatric training at Albert Einstein College of Medicine and advanced training in psychotherapy at the Psychoanalytic Association of New York where she is on the faculty. She focuses on medication management and is holistic in her approach to people and the difficulties they face in life. She has expertise in the treatment of children and adolescents with emotional and behavioral problems, and people struggling with anxiety, depression, bipolar disorder, obsessive-compulsive symptoms, and eating disorders.�

Nazokat Atadjanova, PMHNP

Staff Nurse Practitioner

Dr. Kat Atadjanova is a board-certified psychiatrist dedicated to providing holistic and compassionate care for individuals navigating mental health challenges. She earned her MD from Tulane University School of Medicine and completed a combined residency in Internal Medicine and Psychiatry at Tulane. With experience in both fields, she is especially comfortable caring for patients with medical comorbidities and takes an integrative approach to treatment.

Dr. Atadjanova values collaboration and believes that treatment works best when patients are active participants in their own care. She is committed to creating a safe, supportive environment where patients feel heard and respected. Her approach combines evidence-based medication management with psychotherapy and lifestyle guidance, tailoring each treatment plan to the unique needs and goals of the individual.

In her work, Dr. Atadjanova begins by taking time to understand a patient’s history, strengths, and challenges. From there, she develops a personalized plan that may include medication, therapy, or supportive interventions. She emphasizes shared decision-making, patient education, and holistic strategies—such as nutrition, exercise, and sleep hygiene—to help patients achieve sustainable improvements in their mental health and overall well-being.

Luna Sanchez Rivera, MD

Staff Psychiatrist

Dr. Luna Sanchez Rivera holds the position of Staff Psychiatrist at Talkiatry. After completing residency in 2016 at the Ponce Medical School Psychiatry Residency in Puerto Rico, she then moved to North Carolina to complete a subspecialty in Child and Adolescent Psychiatry at Duke University Health System. There, she transitioned into an assistant professor position, focused on structuring pediatric emergency psychiatric services, and helped support the consult and liaison pediatric service. Her years of experience have included working as an integrated care child psychiatrist within outpatient clinics at Duke University Health System, and she trained and worked as a staff psychiatrist at the Inpatient State Facility in North Carolina. She also served in the Dayton Children's Hospital outpatient clinics in Dayton, Ohio, the Appalachian Health System outpatient clinics in Linville, North Carolina, and more recently has been serving the Child and Adolescent inpatient population in Bangor, Maine. Dr. Sanchez Rivera has an approachable style aimed at providing a comprehensive evaluation for all age ranges and is comfortable managing various levels of diagnostic complexities. She provides supportive psychotherapy while using psychodynamic therapy skills to clarify her patient's constellation of symptoms, identify unifying themes and provide thorough psychoeducation throughout the process to drive positive outcomes. She integrates psychodynamic medication management approaches and is adept at family therapy interventions.

Ready to get matched?

Start our short assessment
Specialties
Anxiety
Bipolar Disorder
Depression
Obsessive-compulsive disorder (OCD)
PTSD/Trauma
Phobias
Postpartum Depression
Geriatric
States
Texas
Utah
Languages
English
Takes insurance
Virtual visits
1 years experience