Our Providers
A multidisciplinary practice offering adult psychiatry, child psychiatry,
clinical psychology and family counseling
Marsh Landing Behavioral Group evolved from Dr. Mark Tomaski's solo child psychiatry practice on Third Street South in Jacksonville Beach. Dr.Tomaski opened this practice in 1996 while practicing as the first child psychiatrist at Nemours Clinic, and consulting for Wolfsons Children's Hospital Psychiatry Unit and Jacksonville's community mental health care system.
With recognition that Northeast Florida offered only fragmented mental health care, he began developing a private group practice to provide comprehensive care to children and families. Marsh Landing Behavioral Group is now an established multidisciplinary practice integrating classic treatment concepts and the modern neurosciences.
Marsh Landing Behavioral Group Specialists provide adult psychiatry, child psychiatry, clinical psychology, and family counseling.
Our providers have a wide range of experience and specialty knowledge in many areas.
Medical Evaluation and Treatment
Mark Christopher Tomaski, M.D.
Dr. Tomaski is a child, adolescent and adult psychiatrist. He specializes in treating young children through early adulthood and often sees adults who are parents of patients. He attributes much of his understanding of childhood mental health to his intensive pediatric and psychiatric training at the University of South Florida, Tampa General Hospital and Moffitt Cancer Center. After training, he became the first child psychiatrist at Nemours Children’s Health. He has been privileged to treat many children and families throughout Northeast Florida over the years. He has a quiet and soft-spoken demeanor that invites interaction and confidence.
Dr. Tomaski formed Marsh Landing Behavioral Group in 2000. He earned an undergraduate degree in biology at Jacksonville University, a medical degree from the University of South Carolina, a pediatric internship at the University of South Florida, an adult psychiatry residency at the University of South Florida and a child psychiatry fellowship at the University of South Florida. He is a member of the American Academy of Child and Adolescent Psychiatry (AACAP).
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Dr. Tomaski was raised in the northern Midwest and moved to Jacksonville as a teenager. He attended local schools and undergraduate colleges in the area. He enjoys time with his family, daily exercise, prayer and occasional kayak fishing.
Alisia Martin, M.D.
Dr. Martin is a child, adolescent and adult psychiatrist, evaluating and treating children from early childhood through early adulthood. Dr. Martin includes patients and their parents in designing treatment plans. She believes that overall health and self-care are part of good mental health. Dr. Martin treats a myriad of conditions including but not limited to, anxiety, depression, autism spectrum disorders, ADHD, obsessive-compulsive disorder, and tic disorders. Most care is provided in her office. Telehealth is available when needed.
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Dr. Martin joined Marsh Landing Behavioral Group in 2002. She earned her undergraduate degree in microbiology from Howard University and a medical degree from the University of Florida. She completed a residency in adult psychiatry and a fellowship in child psychiatry at the University of Florida. She is board-certified and a member of the American Academy of Child and Adolescent Psychiatry (AACAP).
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Dr. Martin is a Florida native and enjoys time with her husband and two children.
Yuliet Sanchez-Rivero, M.D.
Dr. Sanchez-Rivero is a child, adolescent and adult psychiatrist, focusing on helping children and their families improve their quality of life. Her treatment plans for her patients incorporate medication management and therapy. She enjoys treating children and adolescents, as well as young to middle-aged adults. She treats conditions including anxiety, depression, ADHD, obsessive-compulsive disorder, bipolar disorder, and other mixed mood disorders. The majority of her appointments are in her office, with telehealth available as needed. Born in Cuba and raised in Puerto Rico, Dr. Sanchez-Rivero is bilingual in English and Spanish.
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Dr. Sanchez-Rivero joined Marsh Landing Behavioral Group in 2017. She earned her undergraduate degree and medical degree in Puerto Rico. She completed her adult psychiatry residency and her child psychiatry fellowship at the University of Florida. She is board-certified and a member of the American Academy of Child and Adolescent Psychiatry (AACAP).
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Dr. Sanchez-Rivero and her family enjoy spending time traveling and visiting the beach.
Therapy, Counseling and Testing
Cynthia Porter Stevens, Ph.D.
Dr. Stevens is a clinical psychologist who has provided therapy to thousands of individuals of all ages. Her confident and upbeat demeanor helps patients feel at ease quickly. She focuses on problem-oriented, rapid resolution treatment plans that guide clients efficiently toward improvement. Anxiety disorders and OCD are particular areas of her specialization. She utilizes cognitive behavioral therapy (CBT) and exposure response prevention methods, which are widely recognized as the gold standard for treating OCD and anxiety. Dr. Stevens's wisdom, experience, sense of humor, and compassion create a well-rounded experience for all her clients. She also offers Christian integrated care when desired, while working effectively with individuals from all spiritual traditions. She has patients from 6 years of age and older.
Dr. Stevens joined Marsh Landing Group in 2000 during its formation. She earned her undergraduate degree in psychology from Southern Methodist University, a PhD in clinical psychology from the University of Florida, and her internship and residency in clinical and health psychology at the University of Florida. She participates in PSYPACT, which authorizes her to provide virtual sessions to residents of most US states, although most visits take place in her office.
Dr. Stevens enjoys time with her husband and two children. She is active in the International OCD Foundation, fosters canines being trained as service dogs for veterans, and attends a monthly book club. When not working, you might find her at the beach or on a ski slope.
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Jennifer Lynn Wolford, Psy.D.
Dr. Wolford is a clinical psychologist. She employs an eclectic mix of cognitive-behavioral therapy (CBT) and child-centered family systems therapy. She also uses solution-focused therapy, art therapy, and strength-based therapy to help her patients reach their goals. Dr. Wolford specializes in conditions such as anxiety, depression, social phobia, grief, adjustment disorders, and attention disorders. She helps individuals manage divorce and separation, postabortion issues, behavior, development, visual-motor function, and vocation. She works with children from the age of six through young and middle-aged adults. Most treatment is at her office, particularly with children who need and benefit from direct interaction. She also makes time for telehealth visits as needed.
Dr. Wolford joined Marsh Landing Behavioral Group in 2007. She earned her undergraduate degree at the University of Florida and a doctorate in psychology from Regent University. She also completed an internship at the Milton Hershey School and postdoctoral training at a private practice specializing in Clinical Health Psychology.
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When not involved in patient care, she and her family enjoy exploring new adventures.
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Scott Greenaway, Ph.D., ABPP
Dr. Greenaway is a clinical psychologist with experience in teaching and tutoring. He often works with parents and their children, including some who exhibit oppositional and explosive behavior problems. He helps children improve their executive skills, social skills, and develop flexible thinking. Dr. Greenaway understands the milestones of development throughout childhood, adolescence, and early adulthood. He helps patients find a sense of identity and self-awareness, develop healthy relationships, and transition into a meaningful and rewarding adult life. Much of his treatment takes place in his office. Telehealth is also available, and Dr. Greenaway, as a member of PSYPACT, can see patients via telehealth in most states in the US. For more information, go to www.drgreenaway.com or Facebook: www.facebook.com/DrScottSays
Dr. Greenaway joined Marsh Landing Behavioral Group in 2013. He earned his bachelor's degree in education from Pennsylvania State University, his master's degree in clinical psychology from Antioch University, and his PhD in clinical psychology from the University of Texas Southwestern Medical Center. He is board-certified by the American Board of Professional Psychology. He has APA-approved certification in CBT from The Atlanta Center for Cognitive Therapy and APA-approved certification in assessing autism spectrum disorders.
Dr. Greenaway enjoys going on adventures with his wife and children. He has numerous outside interests, including playing guitar in a jazz band, playing the piano, and producing videos to promote mental health awareness. Our group is always interested when a new Stratocaster appears in his office.
Susan Astary, Ph.D.
Dr. Astary is a clinical and school psychologist who has practiced in several states in both private and public school systems. Her treatment emphasizes evidence-based practices, including cognitive behavioral therapy (CBT), and she provides a range of testing services to children and adolescents. Recognizing that children and adolescents are part of many interconnected systems, she uses collaborative partnerships with families, educators and medical providers. Dr. Astary is well-versed in special education (e.g., IEP) and Section 504 processes, as well as in the Multi-Tiered System of Supports/Response to Intervention (MTSS/RtI). She specializes in working with children and adolescents, treating conditions such as anxiety disorders, developmental and behavioral concerns, attention deficit hyperactivity disorder (ADHD), and autism spectrum disorder. Most of her work is done in the office, and telehealth appointments are available when appropriate.
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Dr. Astary joined Marsh Landing Behavioral Group in 2025. She earned her undergraduate degree in psychology and comparative religion from Miami University, a Master's in education degree in school psychology from the University of Florida, and a PhD in psychology from the University of Florida. Additionally, she received training in Supportive Parenting for Anxious Child Emotions (SPACE) treatment.
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Dr. Astary enjoys traveling and spending time with her husband and children.
Janet Campbell, M.A., L.M.H.C.
Janet Campbell is a Licensed Mental Health Counselor. Her approach to care includes therapeutic coaching, cognitive behavioral therapy (CBT), dialectical behavior therapy (DBT), mindfulness-based cognitive therapy, and interpersonal therapy. She specializes in treating pre-teens, teenagers, adults, and families, with issues such as adjustment disorder, life transformations, pregnancy, postpartum depression, grief, anxiety, and major depression. She offers fully virtual appointments with flexible hours to accommodate school and work schedules.
Janet Campbell joined Marsh Landing Behavioral Group in 2000. She earned her undergraduate degree and her master's degree at the University of North Florida
Janet enjoys spending time and traveling with her husband, two children, and her growing extended family. She is a courageous individual who has successfully taken her two teenagers across the country for a multi-week camping trip, towing a fifth wheel.
Annmarie Powell, M.S.W., L.C.S.W.
Annmarie Powell is a Master of Social Work. She specializes in cognitive behavioral therapy (CBT), offering a compassionate approach to adults, teens, and adolescents who are navigating the complex challenges of anxiety, depression, grief, trauma, and adjustment issues. With over 25 years of experience in the field, she has dedicated her career to providing support and counseling to both parents and caregivers as they cope with the emotional and psychological impacts of chronic or terminal illness and other significant life transitions.
Annmarie Powell joined Marsh Landing Behavioral Group in 2013. She earned her bachelor's degree in social work and her master's degree in social work at Florida State University. She completed an internship at Community Hospice of Northeast Florida and served as a supervisor at the Mayo Clinic in Florida. She also worked at Florida State University in the College of Social Work, where she served as a field educator supervising clinical MSW students.
Annmarie enjoys cooking, traveling and spending time with her family.
Tiffany Wood, M.S., L.M.H.C.
Tiffany Wood is a Licensed Mental Health Counselor. Tiffany coaches and counsels teens, college students and young adults using an Acceptance and Commitment Therapy framework. She treats depression, anxiety, ADHD and adjustment issues through a strengths-based approach. She helps clients process and manage difficult thoughts and feelings, and assists them in making decisions that align with their values and goals. She offers spiritually-integrated counseling for those who want to incorporate their Christian faith in treatment. Most care is provided in her office. Telehealth services are also available.
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Tiffany Wood joined Marsh Landing Behavioral Group in 2022. She earned her undergraduate degree in psychology from Georgia Southern University and her master's degree in clinical mental health counseling at the University of North Florida.
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Tiffany is a Jacksonville native and enjoys time with her husband and their dog, Beowulf. She is active in her church, student ministry and women’s Bible study. She has “retro” and “vintage” tastes, and enjoys museums and old books.