Our Providers

Dr. Sydney Kroll Register (currently accepting assessment appointments only)
Dr. Kroll completed her undergraduate degree in Psychology and Women's Studies at The University of Texas at Austin. She then completed her Master's and Doctoral degrees in the Clinical Psychology and Neuroscience department at Baylor University, where she became interested in integrative models of healthcare. During her training, she also developed a passion for working with service members and Veterans at the Waco VA hospital. She then completed pre-doctoral internship training at the UT-Austin Counseling and Mental Health Center, where she focused on the treatment of trauma and the application of mindfulness principles to mental and physical well-being. After completing her doctoral degree, she remained on staff at the UT-CMHC briefly before returning to the Central Texas Veterans Health Care System in Temple, TX. In addition to her work with Veterans, she mentored and supervised doctoral psychology interns, master's level social work interns, and psychiatry residents, and served as Adjunct Professor with Texas A&M/Scott & White Medical School. Dr. Kroll then moved to East Texas and worked at the Charles Wilson VA Outpatient Clinic in Lufkin. She began her private practice in 2009 while in Georgetown, TX, and expanded to full-time practice in April 2014 in Nacogdoches. She continues to dedicate time to serving our nation's heroes, and is an advocate for Veterans' issues both locally and statewide.
Dr. Kroll is licensed in the state of Texas (#34032) and is identified as a Health Service Provider in Psychology by the National Register of Health Service Providers. She has served as President of the Texas Psychological Foundation, and was on the Board of Trustees for the Texas Psychological Association and the Board of the Texas Psychological Foundation for over six years. Her professional affiliations also include the American Psychological Association, the Association for Contextual Behavioral Science, the Collaborative Law Institute of Texas, the Association of Family and Conciliation Courts and the Texas Council on Family Violence. She was appointed by former Governor Rick Perry to serve on the Advisory Council for the Crime Victim's Institute. She has worked in various settings, including the Veterans Health Care System, DoD/Ft. Hood, The University of Texas at Austin, Baylor University, and the Texas Juvenile Justice Department, and has volunteered with the Lone Survivor Foundation, the American Red Cross and the Disaster Emergency Medical Personnel System. She offers trainings and seminars around the country on Acceptance and Commitment Therapy (ACT). Locally, she previously served on the board of the Nacogdoches Area United Way, and currently serves on the boards of Nacogdoches Junior Forum and Community Rx, as well as the Board of Trustees for Christ Episcopal School.
Dr. Kroll provides a wide range of assessment services, specializing in trauma, forensic services and disability determination.. She is trained in several evidence-based treatments for trauma. Dr. Kroll offers concierge individual psychotherapy services, therefore her caseload of individual therapy is rather limited. She is available for one-time consultations to assist in diagnostic clarification and resources.
Dr. Kroll is a native of Nacogdoches, and was excited to return to East Texas in 2012 with her husband, Damon Register, a building contractor, and their son, Lane. She enjoys reading and yoga, as well as spending time outdoors and at her family's wildlife management facility.
Curriculum Vitae
Dr. Kroll completed her undergraduate degree in Psychology and Women's Studies at The University of Texas at Austin. She then completed her Master's and Doctoral degrees in the Clinical Psychology and Neuroscience department at Baylor University, where she became interested in integrative models of healthcare. During her training, she also developed a passion for working with service members and Veterans at the Waco VA hospital. She then completed pre-doctoral internship training at the UT-Austin Counseling and Mental Health Center, where she focused on the treatment of trauma and the application of mindfulness principles to mental and physical well-being. After completing her doctoral degree, she remained on staff at the UT-CMHC briefly before returning to the Central Texas Veterans Health Care System in Temple, TX. In addition to her work with Veterans, she mentored and supervised doctoral psychology interns, master's level social work interns, and psychiatry residents, and served as Adjunct Professor with Texas A&M/Scott & White Medical School. Dr. Kroll then moved to East Texas and worked at the Charles Wilson VA Outpatient Clinic in Lufkin. She began her private practice in 2009 while in Georgetown, TX, and expanded to full-time practice in April 2014 in Nacogdoches. She continues to dedicate time to serving our nation's heroes, and is an advocate for Veterans' issues both locally and statewide.
Dr. Kroll is licensed in the state of Texas (#34032) and is identified as a Health Service Provider in Psychology by the National Register of Health Service Providers. She has served as President of the Texas Psychological Foundation, and was on the Board of Trustees for the Texas Psychological Association and the Board of the Texas Psychological Foundation for over six years. Her professional affiliations also include the American Psychological Association, the Association for Contextual Behavioral Science, the Collaborative Law Institute of Texas, the Association of Family and Conciliation Courts and the Texas Council on Family Violence. She was appointed by former Governor Rick Perry to serve on the Advisory Council for the Crime Victim's Institute. She has worked in various settings, including the Veterans Health Care System, DoD/Ft. Hood, The University of Texas at Austin, Baylor University, and the Texas Juvenile Justice Department, and has volunteered with the Lone Survivor Foundation, the American Red Cross and the Disaster Emergency Medical Personnel System. She offers trainings and seminars around the country on Acceptance and Commitment Therapy (ACT). Locally, she previously served on the board of the Nacogdoches Area United Way, and currently serves on the boards of Nacogdoches Junior Forum and Community Rx, as well as the Board of Trustees for Christ Episcopal School.
Dr. Kroll provides a wide range of assessment services, specializing in trauma, forensic services and disability determination.. She is trained in several evidence-based treatments for trauma. Dr. Kroll offers concierge individual psychotherapy services, therefore her caseload of individual therapy is rather limited. She is available for one-time consultations to assist in diagnostic clarification and resources.
Dr. Kroll is a native of Nacogdoches, and was excited to return to East Texas in 2012 with her husband, Damon Register, a building contractor, and their son, Lane. She enjoys reading and yoga, as well as spending time outdoors and at her family's wildlife management facility.
Curriculum Vitae

Dr. Lisa McCleary (Currently accepting individual and assessment appointments)
Dr.McCleary earned her Bachelor’s of Science in Psychology with a concentration in Developmental Psychology from Castleton University in Vermont in 2006. Then, she completed her Masters of Science in Educational Psychology in 2010 and Ph.D. in School Psychology from the University of Tennessee at Knoxville in 2011. During her studies at the University of Tennessee, she was influenced by a data-based problem solving model and became interested in Applied Behavior Analysis, especially as it applied to child behavior in the school setting. She completed her pre-doctoral internship with the Tennessee Internship Consortium at Lenoir City Schools, where she continued to gain experience in behavioral consultation, psychoeducational assessment, and counseling. Following her pre-doctoral internship, Dr. McCleary continued to grow under supervision of a licensed school psychologist and Board Certified Behavior Analyst during the completion of her post-doctorate at Sweetwater City Schools as a school psychologist and at Blount County Schools in East Tennessee as a behavior specialist. Three years after graduating, Dr. McCleary moved to Nacogdoches and became an Assistant Professor at Stephen F. Austin State University where she taught graduate courses in the School Psychology Program, engaged in research, and directed a pre-doctoral internship for school psychology students at the SFASU Charter School. Although Dr. McCleary enjoyed the University, she missed working directly with teachers and students. From 2016 to 2020, Dr. McCleary worked as the lead behavior specialist at Nacogdoches Independent School District.
Dr. McCleary is a Licensed Specialist in School Psychology (LSSP #70636) and Licensed Psychologist (#36982) by the Texas State Board of Examiners in Psychology (TSBEP). She is also a Nationally Certified School Psychologist (NCSP) by the National Association of School Psychology (NASP). Additionally, she is a Board Certified Behavior Analysist with Doctoral Designation (BCBA-D) by the Behavior Analyst Certification Board (BACB). She has served as the Newsletter Editor and Professional Development Chair forthe Texas Association of School Psychology (TASP).
Dr. McCleary enjoys being active outdoors, yoga, running, and eating very good food. Most of all, she enjoys being present with her husband and two kids.
Dr.McCleary earned her Bachelor’s of Science in Psychology with a concentration in Developmental Psychology from Castleton University in Vermont in 2006. Then, she completed her Masters of Science in Educational Psychology in 2010 and Ph.D. in School Psychology from the University of Tennessee at Knoxville in 2011. During her studies at the University of Tennessee, she was influenced by a data-based problem solving model and became interested in Applied Behavior Analysis, especially as it applied to child behavior in the school setting. She completed her pre-doctoral internship with the Tennessee Internship Consortium at Lenoir City Schools, where she continued to gain experience in behavioral consultation, psychoeducational assessment, and counseling. Following her pre-doctoral internship, Dr. McCleary continued to grow under supervision of a licensed school psychologist and Board Certified Behavior Analyst during the completion of her post-doctorate at Sweetwater City Schools as a school psychologist and at Blount County Schools in East Tennessee as a behavior specialist. Three years after graduating, Dr. McCleary moved to Nacogdoches and became an Assistant Professor at Stephen F. Austin State University where she taught graduate courses in the School Psychology Program, engaged in research, and directed a pre-doctoral internship for school psychology students at the SFASU Charter School. Although Dr. McCleary enjoyed the University, she missed working directly with teachers and students. From 2016 to 2020, Dr. McCleary worked as the lead behavior specialist at Nacogdoches Independent School District.
Dr. McCleary is a Licensed Specialist in School Psychology (LSSP #70636) and Licensed Psychologist (#36982) by the Texas State Board of Examiners in Psychology (TSBEP). She is also a Nationally Certified School Psychologist (NCSP) by the National Association of School Psychology (NASP). Additionally, she is a Board Certified Behavior Analysist with Doctoral Designation (BCBA-D) by the Behavior Analyst Certification Board (BACB). She has served as the Newsletter Editor and Professional Development Chair forthe Texas Association of School Psychology (TASP).
Dr. McCleary enjoys being active outdoors, yoga, running, and eating very good food. Most of all, she enjoys being present with her husband and two kids.

Lauren Ivy Sieja, LCSW (Currently accepting individual appointments)
Ms. Sieja earned her Bachelor of Science in Sociology from Texas A&M University in 2009. Upon graduation, she moved to Austin and began working as an advocate for the National Domestic Violence Hotline, through which she met many social workers who inspired her to pursue a career in social work. Lauren earned her Master of Science in Social Work with a concentration in Community and Administrative Leadership from The University of Texas at Austin in 2014.
Beginning with her practicum in 2012, Lauren worked as a school social worker for eight years in several school districts, including Nacogdoches ISD. Lauren loved being a school social worker because it was the perfect intersection of clinical work with individuals and groups, community outreach, policy creation, and implementation, and program development and evaluation. During her time as a school social worker, Lauren realized her love of facilitating the healing and growth of children, especially pre-teens, adolescents, and young adults. Lauren believes that relationships are the foundation of therapy and approaches sessions by meeting people where they are and using a trauma-responsive, non-judgmental lens. Lauren has had the honor of working with folks of all ages experiencing stress, anxiety, depression, adjustment issues, life changes, grief, and trauma. She also has a strong interest in working with perinatal moms, stressed parents, and caregivers.
Lauren is licensed by the Texas State Board of Social Work Examiners (Licensed Clinical Social Worker #59857). She currently serves as the Region 7 Board Member for the National Association of Social Workers Texas Chapter and has previously served on the Advisory Board for the Lone Star Victims Advocacy Project and Burke Systems of Care.
Born and raised in Nacogdoches, Lauren was excited to move home in 2016. She loves eating chips and queso, enjoys being active outdoors, gardening, cooking, spending time with friends, and watching TV, and savors the time she spends with her husband and two kids.
Curriculum Vitae
Ms. Sieja earned her Bachelor of Science in Sociology from Texas A&M University in 2009. Upon graduation, she moved to Austin and began working as an advocate for the National Domestic Violence Hotline, through which she met many social workers who inspired her to pursue a career in social work. Lauren earned her Master of Science in Social Work with a concentration in Community and Administrative Leadership from The University of Texas at Austin in 2014.
Beginning with her practicum in 2012, Lauren worked as a school social worker for eight years in several school districts, including Nacogdoches ISD. Lauren loved being a school social worker because it was the perfect intersection of clinical work with individuals and groups, community outreach, policy creation, and implementation, and program development and evaluation. During her time as a school social worker, Lauren realized her love of facilitating the healing and growth of children, especially pre-teens, adolescents, and young adults. Lauren believes that relationships are the foundation of therapy and approaches sessions by meeting people where they are and using a trauma-responsive, non-judgmental lens. Lauren has had the honor of working with folks of all ages experiencing stress, anxiety, depression, adjustment issues, life changes, grief, and trauma. She also has a strong interest in working with perinatal moms, stressed parents, and caregivers.
Lauren is licensed by the Texas State Board of Social Work Examiners (Licensed Clinical Social Worker #59857). She currently serves as the Region 7 Board Member for the National Association of Social Workers Texas Chapter and has previously served on the Advisory Board for the Lone Star Victims Advocacy Project and Burke Systems of Care.
Born and raised in Nacogdoches, Lauren was excited to move home in 2016. She loves eating chips and queso, enjoys being active outdoors, gardening, cooking, spending time with friends, and watching TV, and savors the time she spends with her husband and two kids.
Curriculum Vitae