Camille Mendez-Maldonado, MD

Dr. Carmen Orellana is a Staff Psychiatrist at Talkiatry who has been in practice for over 6 years, both in the U.S. and abroad. She is double board-certified in child and adolescent psychiatry and adult psychiatry. Dr. Orellana's practice focuses on medication management. She strives to provide exceptional medical care and has extensive experience in treating persons with diverse behavioral disorders and backgrounds. Dr.Orellana involves her patients in all decisions about their health, and provides care that is respectful of patient preferences, needs, and values. Typically, she would recommend evidence-based treatments to her patients and may, occasionally, believe that concurrent therapy is also needed. She would ask that you bring a therapist into your care team to provide the best outcome. Dr.Orellana received her medical degree from Universidad Evang�lica de El Salvador. Dr. Orellana completed a residency in Psychiatry and a fellowship in child and adolescent psychiatry at the Southern University School of Medicine in Springfield, Illinois. After completing her training, Dr. Orellana remained in the school, where she worked as an Assistant Professor of Child and Adolescent Psychiatry, supervising and teaching medical students, residents, and fellows, and treating patients with various psychiatric conditions. Dr. Orellana has experience in treating treatment-resistant mood disorders with electroconvulsive therapy (ECT) and transcranial magnetic stimulation (TMS).‍

Matthew Twomey, PMHNP, earned his BSN and MSN from the Massachusetts General Hospital Institute of Health Professions School of Nursing. He began his career as an adult psychiatric nurse practitioner in community health centers before commissioning as an officer in the U.S. Army Nurse Corps. After five years of active duty, he continued caring for service members and families at Fort Bliss as a civilian provider for nearly six years. He now practices in the private sector, bringing broad clinical experience to diverse patient populations.

Matthew is skilled in psychopharmacology, evidence-based practice, and telehealth delivery. He combines strong clinical expertise with a patient-centered approach to improve outcomes and streamline care. Patients can expect thoughtful collaboration, clear communication, and treatment planning grounded in the latest research and tailored to their individual goals.

He specializes in psychopharmacology and precise medication management tailored to each patient’s unique needs. He also integrates supportive psychotherapy, motivational interviewing, psychoeducation, and cognitive behavioral therapy. Through active listening and mutual respect, he fosters a safe, supportive environment where patients feel heard, engaged, and empowered in their care.

Pamella Bess-Tabb is a Licensed Clinical Social Worker (LCSW, LICSW) and Certified Advanced Social Work Case Manager (C-ASWCM) with nearly a decade of experience across behavioral health, medical, educational, and community settings. She has supported adults and children navigating ADHD, anxiety, depression, and life transitions, using a practical, trauma-informed approach that emphasizes real-world tools and growth.

Pamella takes a collaborative, down-to-earth approach. She values authenticity, respect, and tailoring care to each person’s needs. Patients can expect a supportive partner who meets them where they are, helping them feel heard, understood, and empowered.

Her methodology blends CBT, Motivational Interviewing, and Mindfulness. Pamella focuses on executive functioning, coping strategies, and practical habits that reduce overwhelm. Through therapy and case management, she helps patients build skills that lead to sustainable change and greater confidence in managing life’s challenges.

Dr. Pressley Warrick is a double board-certified psychiatrist specializing in general psychiatry and child and adolescent psychiatry. Dr. Warrick currently practices full-time, offering comprehensive psychiatric care to children, adolescents, and adults. She previously established and led a Behavioral Health Clinic integrated within a Family Medicine Practice. Prior to this role, Dr. Warrick provided dedicated psychiatric care at a private psychiatry practice for over a decade.

Dr. Warrick earned her medical degree from the Medical University of South Carolina, completed residency training at Baylor College of Medicine's Menninger Department of Psychiatry and Behavioral Sciences, and pursued additional specialization through a Child and Adolescent Psychiatry fellowship at Palmetto Health/USC School of Medicine.

Known for a collaborative and holistic treatment approach, Dr. Warrick emphasizes individualized care and evidence-based practices to support patients’ mental wellness. Her professional excellence has earned recognition as Sumter’s Best Psychiatrist for consecutive years.

Dr. Warrick’s preferred treatment modalities include medication management, psychodynamic psychotherapy, and supportive psychotherapy. She specializes in treating depression, anxiety, ADHD, autism, OCD, bipolar disorder, and PTSD. Her typical approach for new patients involves taking a detailed patient history, establishing rapport, and setting clear treatment goals in partnership with her patients.

Dr. Kathryn Bertacchi is board-certified in both adult and child & adolescent psychiatry. Originally from California, she earned her medical degree from University College Cork in Ireland and completed residency and fellowship at Emory University. She has practiced in varied settings, including developing specialized clinics in eating disorders and gender-affirming care. She is a member of several professional organizations including AACAP, APA, and WPATH.

Dr. Bertacchi fosters an inclusive, nonjudgmental environment where patients feel safe to be themselves. She approaches care with curiosity, compassion, and deep respect for each person’s unique story, aiming to help individuals feel genuinely heard and supported throughout their treatment journey.

In early sessions, Dr. Bertacchi works collaboratively to understand patients' lives, goals, and challenges. While her focus is medication management, she integrates cognitive-behavioral, humanistic, and supportive techniques. She may recommend additional therapy as needed and particularly values working with youth and adults from diverse backgrounds.

Bethany McCann is a board-certified Adult and Forensic Psychiatrist. After obtaining her Bachelor of Arts degree in Psychology at Kent State University, she received her medical degree from Ohio Heritage College of Osteopathic Medicine. She then went on to complete her Psychiatry Residency training at The Ohio State University, where she served as a Chief Resident for two years.

Following residency, Dr. McCann pursued an additional year of training through Ohio State, where she completed a Forensic Psychiatry Fellowship. A large portion of her time was spent in the state hospital system, where she learned more about the interplay between psychiatry and the law, provided high-quality psychiatric services to an inpatient forensic population, conducted forensic evaluations, and educated the Court on psychiatric topics through expert testimony.

While Dr. McCann has had experience working in a variety of settings, she has maintained a passion for outpatient psychiatry and building a strong, therapeutic relationship with her patients. Dr. McCann will provide an evidence-based medication management visit for a variety of psychiatric conditions including depression, anxiety, bipolar disorder, ADHD, PTSD, and OCD, while incorporating therapeutic techniques that are tailored to the individual and their goals.

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