Joshua Weasen, MD

Dr. Diane Papke holds the position of staff psychiatrist at Talkiatry. After graduating from medical school, she completed internship year in Internal Medicine at St. Joseph's Hospital in Phoenix, AZ, followed by two years of neurology residency at Barrow Neurological Institute before completing Psychiatric residency at Maricopa Medical Center in 2005. She then spent the majority of her time caring for SMI/seriously mentally ill patients with a mantra "propelling people forward to wellness.” Working on the supportive level of care for this population honed her skills to care for the highest level of outpatient care through ACT/assertive community treatment. She has a genuine interest in treating psychiatric disorders including anxiety, depression, PTSD, OCD, ADHD, and most specifically bipolar. She has experience treating medical comorbidities including neurologic disorders. In 2023, she extended her expertise and skills to the general population to include telehealth management of her patients. With a nonsense approach, she prides herself on collaborating with patients to attain their goals of optimum psychiatric health, believing that the cornerstone of a healthy partnership with any patient is a holistic approach. Listening with an open mind and heart while collaborating with her patients to provide the correct medication management and supportive care has always been the key for her. She is looking forward to meeting you!

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. Rodriguez is a board-certified adult psychiatrist. He earned his medical degree from the David Geffen School of Medicine at UCLA and completed his residency at the University of Southern California. Dr. Rodriguez has experience working in a variety of settings, including inpatient, outpatient, community mental health, and correctional facilities.

Dr. Rodriguez specializes in treating depression and anxiety. He acknowledges that while medications can be necessary, they are not magic, and a holistic approach is essential for achieving mental health. With this understanding, Dr. Rodriguez spends time getting to know his patients, focusing on helping them achieve mental wellness rather than simply prescribing medications. When he became a doctor, he made a pledge to "do no harm." He takes this commitment seriously and only prescribes medications, especially those with addictive properties, when it is safe and clearly indicated.

The first one or two appointments focus on a thorough assessment to establish a provisional diagnosis, which is essential for effective treatment planning. Once this initial diagnosis is made, Dr. Rodriguez collaborates with his patients to develop tailored treatment recommendations. During follow-up appointments, he actively listens to his patients and proposes adjustments to the treatment plan as needed.

Dr. Claudia Cao is a board-certified psychiatrist. She earned her medical degree and completed her general psychiatry residency at the University of Michigan, followed by a fellowship in psychodynamic psychotherapy through the Michigan Psychoanalytic Institute. Prior to psychiatry, Dr. Cao was a board-certified anesthesiologist and completed her anesthesia residency at UCLA and an obstetric anesthesia fellowship at Mass General Brigham.

Dr. Cao takes a multimodal approach to mental health care, integrating medication management, psychotherapy, lifestyle changes, and integrative methods. She values personal connection and believes that understanding each patient’s story is central to effective treatment. Her goal is to support patients in improving their quality of life in a collaborative and compassionate environment.

Dr. Cao spends the first several visits listening closely to understand each patient’s concerns, goals, and experiences. She then partners with patients to develop a personalized treatment plan. Ongoing visits are tailored to each individual’s needs and may evolve as treatment progresses.

Dr. Megan Marumoto provides holistic and personalized care as an integrative psychiatrist board-certified in General Psychiatry, Child & Adolescent Psychiatry, Integrative Medicine, and Lifestyle Medicine. She takes a root cause approach to treating mental health conditions as a certified Functional Medicine practitioner. Dr. Marumoto treats a wide range of mental health conditions in children, adolescents, and young adults, including ADHD, anxiety, depression, phobias, OCD, and trauma-related conditions. Patients may expect a comprehensive assessment with evidence-based treatment focusing on nutrition and healthy lifestyle interventions as well as medication management in 20�30-minute sessions. She enjoys working collaboratively with therapists and health coaches to achieve the best outcomes. She also provides supportive therapy and other therapies when indicated. She received her medical degree from the John A Burns School of Medicine and completed her Psychiatry Residency and Child & Adolescent Psychiatry fellowship at the University of Hawaii. Wishing to provide comprehensive care beyond medication management and therapy, Dr. Marumoto completed a second fellowship in Integrative Medicine at the University of Arizona. She has over 20 years of clinical experience working with military and civilian populations.

Dr. Thistlethwaite is a board eligible adult psychiatrist and internal medicine physician. He completed his medical education at West Virginia University School of Medicine. Following completion of medical school, Dr. Thistlethwaite completed residency training at WVU/Charleston Area Medical Center with a dual specialization in internal medicine and psychiatry. Dr. Thistlethwaite's training included treatment of patients both in the inpatient and outpatient setting as well as management of patients with comorbid medical conditions. During his training Dr. Thistlethwaite became passionate about approaching patients in a holistic manner that addressed both their physical and mental health. He is especially passionate about ensuring that patients with mental health disorders are provided with appropriate general medical care as they are a marginalized and underserved group. Dr. Thistlethwaite's practice focuses on medication management for a wide array of conditions including depression, anxiety disorders, bipolar disorder, obsessive compulsive disorder, tic disorder/Tourette's, and post traumatic stress disorder. Dr. Thistlethwaite incorporates supportive psychotherapy, cognitive behavioral therapy interventions, and some psychodynamic therapy skills in his practice as well. Dr. Thistlethwaite believes in a collaborative and holistic approach to mental healthcare that incorporates the patient as well as all members of the healthcare team in every aspect of care.