Shannon D. Mullen, Ph.D.
Shannon D. Mullen completed her Ph.D. in Psychology from The University of Tennessee in Knoxville, Tennessee. Dr. Mullen is a licensed psychologist in the state of Georgia. Prior to her doctoral studies, Dr. Mullen completed a Master of Arts in Counseling at the University of New Orleans. Dr. Mullen established Mosaic Psychological Services where she provides clinical and forensic services.
Mandy B. Mullen, LCSW
Mandy B. Mullen is a Licensed Clinical Social Worker in both Georgia and Florida. Ms. Mullen received a B.S. in Human Services and has a Masters of Social Work from Florida Gulf Coast University in Fort Myers, Florida. Her current professional specialities are play therapy, trauma counseling, child and adolescent behavioral problems as well as marital therapy and relationship counseling. She is certified in Trauma Focused Cognitive Behavioral Therapy (TF-CBT). Ms. Mullen is also the System of Care Director and is responsible for ensuring the best patient experience for receiving services at Mosaic.
Destin N. Stewart, Ph.D.
Destin Stewart, Ph.D. is a licensed psychologist in the state of Georgia and specializes in the evaluation and treatment of children, adolescents, and adults. Dr. Stewart completed her undergraduate education at Florida State University with a major in Psychology and an emphasis on Psychology of Religion. She completed a Master degree in Clinical Psychology at Mississippi State University and then went on to obtain a Ph.D. in Psychology from The University of Tennessee. Dr. Stewart received the Marcia Katz Scholarship from the Knoxville Association of Women Executives during her doctoral studies. She completed her pre-doctoral clinical internship at the University of Florida Counseling and Wellness Center. Her professional interests include forensic evaluation, psychological and psychoeducational assessment, women’s mental health broadly defined, and sexual trauma. Additionally, Dr. Stewart has specialized training in adult neuropsychological assessment, as she trained at the University of Tennessee Medical Center’s Neuroscience Clinic. Dr. Stewart has held placements at two major university counseling centers, several hospitals and outpatient clinics, and private practice. Dr. Stewart has published several peer-reviewed publications in the fields of forensics, psychology of gender, and the psychology of religion. She has also published a text book chapter and has had her research featured in the American Psychological Association’s Monitor. Her research has also been featured online at NBCnews.com and other news-related websites.
David Valpuesta, MFT
David Valpuesta received his Master's of Science in Marriage and Family Therapy from Valdosta State University. Prior to obtaining his Master's degree, Mr. Valpuesta received his Bachelor of Science in Psychology from Florida State University. As a Marriage and Family Therapist, he understands that when people experience trauma or severe stressors, life may seem to unravel. It is his passion to help couples, families, and individuals experiencing martial or relational conflicts, adolescent behavioral problems, and bereavement issues.
Rachelle H. Cantin, Ph.D., NCSP
Dr. Cantin obtained her undergraduate degree at Albion College, where she majored in psychology and graduated with honors. Dr. Cantin received her Ph.D. in School Psychology from Illinois State University’s. While at Illinois State, Dr. Cantin was bestowed the Ora Bretall Graduate Fellowship and University Fellowship. She completed specialized training in neuropsychological assessment, with an emphasis on executive functioning. Dr. Cantin concluded her doctoral studies with a clinical internship at the APA-approved Florida State University Multidisciplinary Center in Tallahassee, FL. She subsequently completed her postdoctoral fellowship at Georgia Pediatric Psychology in Atlanta, GA, with a primary focus on the assessment and treatment of Autism Spectrum Disorder. She has extensive experience in the assessment and treatment of developmental, educational, and behavioral disorders among child and adolescent populations, with an additional specialization in Autism Spectrum Disorder, intervention, and educational consultation.
Martha J. Walter, Ph.D
Dr. Walter obtained her Ph.D. in School Psychology from the University of Wisconsin-Madison. Prior to finishing her Ph.D., she completed her doctoral clinical internship at the Florida State University Multidisciplinary Evaluation and Consulting Center in Tallahassee, FL. She subsequently completed her postdoctoral fellowship in the Developmental Medicine Center at Boston Children's Hospital/Harvard Medical School in Boston, MA. Dr. Walter has extensive clinical experience in the assessment and treatment of children, adolescents, and young adults with a range of social-emotional, behavioral, and academic difficulties. She has particular expertise in assessment of Autism Spectrum Disorder, Intellectual Disabilities, Learning Disabilities, and ADHD; early childhood assessment; intervention for Selective Mutism and other Anxiety Disorders; and school consultation.
Billing and Credentialing Specialist
Candace Strickland, BS