Marcia Morris, MD

For the past 20 years, Dr. Lavin has worked at the University of Denver Health and Counseling Center, where she has treated undergraduate and graduate students. She also worked at a training clinic for students pursuing their PsyD degree. She has supervised and taught psychiatry residents. She taught a psychopharmacology and differential diagnosis course to psychology trainees. Dr. Lavin has a strong interest in functional medicine and alternative therapies. Dr. Lavin has been in practice for 35 years. She is board certified in adult psychiatry. Dr. Lavin focuses on a comprehensive medical assessment, medication management, psychoeducation, wellness, and alternative therapies. She enjoys treating young adults. Dr. Lavin did her undergraduate work at the University of Rochester. She earned her MD from Cornell University Medical College in New York City. Her psychiatry residency was at the University of Boston Medical Center. After training, Dr. Lavin held administrative and clinical positions at Kaiser Permanente in Denver, CO and at the Harvard Community Health Plan in Braintree, Massachusetts. She has written clinical triaging guidelines and patient information pamphlets.‍

Dr. John Hendrick is a practicing psychiatrist who has recently served as medical director for clinical services at Erlanger Behavioral Health Hospital in Chattanooga, TN. After several years of private practice, he had served as Chief of Inpatient Psychiatric Services and then as Chief of Psychiatry at Mountain Home VA Medical Center. During his time at Mountain Home VA he was also a Professor of Psychiatry at Quillen Medical School at East Tennessee State University where he taught General Psychiatry courses and the Neurosciences of Psychiatry. His specialties include affective and anxiety disorders and he has specific expertise in neuropsychiatry, psychopharmacology and alternative treatments for affective disorders. He is a Distinguished Life Fellow of the American Psychiatric Association and is a Past President of both the Tennessee Psychiatric Association and the Southern Psychiatric Association. He has been awarded a Distinguished Service Award from the United States Public Health Service. He has been twice named the Outstanding Teacher Award from the ETSU Psychiatry Residency program and was awarded Course Director of the year for the Neurosciences residency course he developed. He holds an Irma J. Bland Award for Excellence in Psychiatric Education from the APA. He has an extensive psychiatric background in practice and as a teacher. He practices psychotherapy from an Eriksonian perspective and is well versed in individual and psychodynamic psychotherapies.

Dr. Catherine Shim is a board-certified psychiatrist and completed her training at the University of Washington, where she received additional certifications in Psychotherapy and Community Psychiatry.  Prior to joining Talkiatry, she spent years serving the mental health needs of underserved communities as well as our Veteran population.  Dr. Cat is excited to bring that same dedication and selfless service to her Talkiatry patients!

Dr. Cat is experienced in managing a multitude of mental health conditions, but her specialty is providing behaviorally oriented trauma-informed care.  Her approach is to treat primarily through psychotherapy and behavioral change, with medication management serving as an important (and often essential) adjuvant to optimizing mental health.

Dr. Cat tends to have a very casual engagement style, so expect a frank but open conversation during your first meetings with her.  Following that initial screening, anticipate a candid discussion about her approach to your condition and an initial treatment plan.  Please feel free to bring up any questions or concerns at any time during this process, and note-taking is highly encouraged!

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Dr. Michael Gravenstein earned his medical degree from the University of Florida College of Medicine, where he also completed his psychiatry residency. During training, he was recognized with multiple awards, including the Malcom Randall VA Resident of the Year Award, the Ross A. McElroy Psychotherapy Award, and the John “J.D.” Dorian Award for best sense of humor. He has worked across outpatient, inpatient, and consult liaison settings, and has experience treating a wide range of conditions including depression, anxiety, ADHD, OCD, personality disorders, and transitional age concerns. He also has expertise working with LGBTQIA+ patients and provides psychodynamic, CBT, and supportive therapies.

Dr. Gravenstein believes in a comprehensive approach to treatment that integrates medications, therapy, and lifestyle interventions. While medications can be very effective, he views them as just one part of a broader treatment plan tailored to each patient’s needs. He emphasizes individualized care and sees treatment as a team effort, meeting patients where they are and progressing at a pace they feel ready for.

Dr. Gravenstein strives to create a warm, collaborative environment that fosters open communication and genuine connection. He may challenge patients therapeutically but always with careful attention to their readiness and comfort. His goal is to build trust so that meaningful conversations and progress can occur. For him, success is always shared—when patients succeed, they succeed together; when challenges arise, they regroup and move forward together.

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.

Erika Zarco is a Licensed Marriage & Family Therapist and Telehealth provider. She has extensive experience working in non-profits, schools, academic settings, and private practice. Erika is certified in Trauma-Informed Interventions, Advanced Grief Counseling, Addictions-Informed Care, Narrative Therapy, Emotional Freedom Techniques (EFT), Solution-Focused Brief Therapy, and Nutrition & Integrative Medicine for trauma. She holds a BA in Humanities from New College of California and a master’s in Counseling from the Wright Institute.

Erika values open communication and helps clients set clear treatment goals. She fosters a collaborative environment using narrative counseling, Internal Family Systems, and “parts” work to help clients re-story their experiences. She also offers EFT Tapping for trauma, anxiety, depression, and pain. Erika works from the belief that clients are the experts in their own lives and promotes self-determination through Motivational Interviewing, Harm Reduction, and Energy Psychology.

Erika begins by understanding what brings clients to therapy and building a strong therapeutic relationship. She tailors Narrative Counseling and EFT sessions to each individual, collaboratively creating personalized treatment plans with achievable, transformational goals. Her approach is holistic, supportive, and designed to empower clients to recognize their strengths and motivation for meaningful change.