Jaime Sather, PMHNP

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.

Dr. Adeola Mustapha is a board-certified psychiatrist with experience across outpatient, inpatient, and community mental health settings. She completed her psychiatry residency at Indiana University School of Medicine – Vincennes in July 2024 after earning her medical degree from Ross University School of Medicine. Recognized for her exceptional psychotherapy skills, Dr. Mustapha received therapy awards in both her PGY3 and PGY4 years. Her background reflects a commitment to blending strong clinical training with compassionate, patient-focused care.

Dr. Mustapha creates a warm, collaborative, and supportive environment where patients feel respected and understood. She believes in the power of psychotherapy combined with evidence-based psychiatric care, always striving to integrate both in treatment. Open communication and clear, realistic goal setting are central to her approach. She is committed to a holistic perspective that considers emotional, physical, cultural, and social well-being. With an emphasis on empowerment, Dr. Mustapha encourages patients to take an active role in their healing journey.

Dr. Mustapha begins with a comprehensive evaluation to learn each patient’s history, concerns, and goals. She develops individualized treatment plans that may integrate therapy modalities such as CBT, DBT, TF-CBT, psychoanalysis, and FETI, along with medication management when appropriate. Using a goal-oriented, step-by-step process, she tracks progress and adapts treatment as needs evolve. Through ongoing dialogue, she ensures patients feel supported, informed, and engaged throughout their care. Her aim is to foster long-term resilience and overall wellness, not just symptom relief.

Dr. John Lundeen earned his medical degree from the Medical College of Georgia and completed his psychiatry residency at TriStar Centennial Medical Center. He has worked with adults of all ages in both outpatient and inpatient settings, bringing a wide range of experience to his practice.

Dr. Lundeen approaches every patient with respect, empathy, and a genuine desire to understand their unique experience. He recognizes that seeking treatment can be intimidating and strives to create a welcoming, non-judgmental environment where patients feel safe and heard.

Dr. Lundeen believes in a collaborative treatment process, prioritizing each patient’s goals, values, and input. He emphasizes mental health education as a core component of care, empowering patients to better understand their treatment options and take an active role in their well-being.

Dr. Dennis Valerstain is a board-certified Adult and Child and Adolescent Psychiatrist. After completing his undergraduate education at Emory University, he attended medical school at the Northwestern University Feinberg School of Medicine. He subsequently completed psychiatry residency at University of Miami/Jackson Health System and further sub-specialized at University of Miami/Jackson Health System with a fellowship in Child and Adolescent Psychiatry. Dr. Valerstain has had the opportunity of working with a diverse array of patients including children, adolescents, the severely mentally ill, veterans, and cancer patients across three distinct hospital systems. Dr. Valerstain has had varied clinical experiences in specialty inpatient psychiatry units, emergency psychiatry, consultation liaison psychiatry, psycho-oncology, and outpatient clinics via telemedicine and face to face interactions. Dr. Valerstain has experience working with patients of all ages, particularly those with depression, anxiety, bipolar disorder, ADHD, Tic disorders, substance use disorders, and more. Dr. Valerstain's practice focuses on medication management and also 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 (and their families) to navigate their complex issues and jointly focusing on simple solutions to work towards improving their mental health.

Dr. Megan Tusken is a board-certified adult psychiatrist. She received her undergraduate degree from Brown University and her medical doctorate at the University of Chicago Pritzker School of Medicine. Prior to joining Talkiatry, Dr. Tusken completed residency training in general psychiatry at the University of Texas Southwestern Medical Center. Dr. Tusken provides evidence-based, patient-centered care and considers a trusting doctor-patient relationship integral to helping her patients achieve their treatment goals. During training, Dr. Tusken gained extensive experience in inpatient, consult, emergency room, and outpatient practice settings with culturally and socioeconomically diverse patient populations. She also elected to acquire additional experience with specific patient populations, including patients with treatment-resistant depression, substance use disorders, and sleep disorders, as well as LGBTQ+ individuals and older adults. Tusken's treatment approach is collaborative and holistic. She provides medication management for a variety of mental health conditions, with particular interest in mood and anxiety disorders. In addition to psychopharmacologic interventions, she firmly believes in the mind-body connection, and she incorporates psychotherapeutic techniques into her visits to provide the best, individualized care for each patient.

Patricia Grendell is a board-certified Psychiatric-Mental Health Nurse Practitioner who provides mental health care using a personalized, holistic approach. Patricia specializes in psychiatric evaluation and medication management along with psychotherapy and integrative interventions. Prior to receiving education and training in Nursing at New York University and Case Western Reserve University, Patricia earned a Master of Social Work from Boston College with a focus on health and mental health.  

Patricia specializes in working with adults experiencing a wide range of acute and chronic stressors and mental health symptoms. Patricia tailors' treatment to the goals, needs, and comfort level of each individual at her or his own pace. Patricia builds connections with patients so that they feel heard and understood, and partners with each individual to determine the most appropriate treatment strategies that maximize comfort, safety, and positive results.  

Over the past ten years as a Nurse Practitioner in outpatient and inpatient environments, Patricia has helped patients improve and overcome conditions including depression, anxiety, OCD, PTSD, ADHD, and insomnia. Using a combination of medication management, individual therapy, and psychoeducation, Patricia develops individualized treatment plans centered around patients’ priorities and safety to achieve improvements in health and quality of life.