Kevin Nieman, Ph.D., LMFT, Director
Dr. Kevin Nieman, LMFT, is the founder and director of Cornerstone Christian Counseling Services (CCCS). Dr. Nieman earned his doctorate in Marriage and Family Therapy from the University of Louisiana at Monroe (ULM), a master’s degree in Marriage and Family Therapy from Harding University, and an undergraduate degree in Business Management from Harding University. Dr. Nieman is a Clinical Member of the American Association for Marriage and Family Therapy (AAMFT), the Oklahoma Association for Marriage and Family Therapy (OKMFT). He is also a member of the American Association of Christian Counselors (AACC). He is an AAMFT Approved Supervisor in Marriage and Family Therapy. Dr. Nieman is also certified to provide Mediation services. He also serves as Adjunct Professor at Southern Nazarene University in their graduate program.
Dr. Nieman has a passion for helping hurting people find hope and healing. Areas of specialty and interest include marriages in crisis, differentiation and self-worth development, and working with CEOs and professional athletes.
Dr. Nieman is married to Lindsey Nieman, M.A. who also provides Marriage and Family Therapy at CCCS. Together they have two beautiful boys. Dr. Nieman is an avid Green Bay Packers Fan. He enjoys doing co-therapy with his four-legged friend, Bailey.
Lindsey Nieman, M.A., RDN, LD LMFT
Lindsey Nieman, M.A. is a staff therapist at Cornerstone Christian Counseling Services (CCCS). She earned her Master of Arts in Marriage and Family Therapy and an undergraduate degree in Business Management from the University of Louisiana at Monroe (ULM). She also has an undergraduate degree is Nutrition and Dietetics from Louisiana Tech University. Lindsey finished her dietetic internship through the University of Oklahoma Health Science Center. She is a registered dietitian as well as a Licensed Marriage and Family Therapist. Lindsey is a member of the Academy of Nutrition and Dietetics and the American Association of Christian Counselors.
Lindsey is passionate about helping individuals achieve a healthy lifestyle both physically and emotionally/mentally. She combines her knowledge from the nutrition perspective with her Marriage and Family Therapy training to provide her clients with a more complete approach to health. She coordinates healthy lifestyle and cooking classes and groups.
Lindsey is married to Dr. Kevin Nieman, founder and director of CCCS. Together they have two beautiful boys. Lindsey enjoys and is passionate about exercise, gardening, and cooking.
Dawn Brandenburgh, M.Ed., LPC
Dawn Brandenburgh, M.Ed., LPC-S is a staff therapist at Cornerstone Christian Counseling Services (CCCS). She graduated from Ohio University with a Master of Education in Community Counseling. She earned her Bachelor of Science degree in Psychology from Texas A & M University. Dawn worked as a Licensed Professional Counselor in Wisconsin for over 10 years as well as clinically supervised candidates towards licensure before her family relocated to Tulsa in 2013.
Dawn has a passion to help clients who desire an increased awareness and insight into their lives – working towards the goal of healing and the installation of hope – and help them recognize the power and influence they have to make changes in their lives. Early in her career, Dawn worked with at-risk adolescents in various residential facilities. These experiences taught her to look beyond a person’s behavior and instead encouraged her to seek to understand what set of circumstances helped shaped their current behaviors. For some who experienced difficult and/or traumatic events in their lives, they responded to their circumstances by engaging in adaptive behaviors. Dawn works intentionally to help her clients understand that although once helpful and at times life-saving, some of these strategies may no longer be as effective as they once were.
Dawn has experience working with a diverse group of clients, including those who struggle with self-esteem issues (‘people pleasers’), anxiety, depression, unresolved trauma and adjustments to life circumstances (school, empty nest, relationships, job loss, etc.). In her work with clients, Dawn strives to create an atmosphere of non-judgment and safety—with the aim of decreasing resistance and ultimately allowing for client growth.
Dawn is also an Approved Supervisor for candidates seeking licensure as a Licensed Professional Counselor in Oklahoma.
Dawn and her husband have been married since 1996. Together they have two beautiful children, whom they homeschool. Dawn enjoys reading, running and spending time with her family.
Dawn is an in-network provider for many insurance companies.
Mike Blacet, M.S.W., LCSW
Mike Blacet, LCSW earned his Master of Social Work from the University of Oklahoma and is a Licensed Clinical Social Worker in Oklahoma. He is a member of the American Association of Christian Counselors.
Mike is committed to helping others, in cooperation with Christ’s work in them, to overcome obstacles and difficulties in their lives. Mike’s areas of specialty and interest include parent/child relationship problems, attachment issues, anxiety, anger, and spiritual issues.
Mike and his wife Angela have been married since 2001. They are grateful for time together as a family with their two daughters and their son.
Mike enjoys running, reading, studying the sciences, working with his hands, and spending time with family and friends.
Cecilie Croissant, LPC
Cecilie Croissant, MA, LPC earned her Master’s degree in Marriage and Family Therapy from Southern Nazarene University and is a licensed professional counselor in Oklahoma. In addition, Cecilie received Christian Leadership training from William Jessup University and Impact International School of Ministry. Cecilie is an adjunct professor at Southern Nazarene University and Oklahoma Wesleyan University. She worked as an inpatient therapist at Tulsa Women and Children’s Center, an intensive substance abuse program. Cecilie has an extensive background in Christian ministry and is a member of American Association of Christian Counselors.
Cecilie is passionate about helping people discover the path to lasting transformation. She has worked with people of different ages and cultures including those with addiction and substance abuse issues, people with mood and anxiety issues, and those with unresolved grief and trauma. She desires to see individuals, marriages, and families restored and help people overcome and grow past longstanding negative patterns.
Cecilie and her husband have been married for 33 years and have two adult daughters. Cecilie enjoys being with family, various forms of ministry, playing keyboard and piano, writing, a nice meal with friends, and a good laugh.
Marc Clayton, M.A., LMFT Candidate
Marc earned his master’s degree in Marriage and Family therapy from Southern Nazarene University. He is a registered Licensed Marriage and Family Therapist Candidate with the State of Oklahoma.
Marc previously worked in the Chemical Dependency Intensive Outpatient Program at Laureate Psychiatric Clinic & Hospital. Marc currently serves as a Recovery Minister at Park Plaza Church of Christ.
Marc is committed to helping individuals and couples find themselves through God’s healing power. Marc will walk with you as you open the door to therapy by sharing your experiences, strengths, and hopes as well as your willingness to accept God’s grace in solving life’s problems. This freedom creates peace, serenity, joy and most importantly a stronger relationship with the Trinity – God, Christ, & Spirit.
Marc and his wife, Jamie, married in March of 2002 and have two beautiful daughters who enjoy camping, hiking, and fishing.
Paul Cochran, M.D., Psychiatrist
Paul Cochran grew up in the Seattle area, attended Washington State University as an under grad, and medical school at the University of Oklahoma from 1974 to 1978. He did a family practice residency until 1981 but practiced emergency medicine until June of 2004 at which time he left emergency medicine to pursue psychiatry, and completed a residency program in psychiatry in 2007 at Griffin Memorial Hospital. Paul has specialty boards in Family Medicine, Emergency Medicine & in Psychiatry, and he was elected a Fellow in Emergency Medicine in 2002.
Since residency, Paul has worked at Tulsa Center for Behavioral Health, L.E. Rader Center (adolescent corrective institution). Most recently, Paul has worked at Brookhaven Neuropsychiatric Institute which treats brain injured patients with co existing behavioral disorders, and has a private practice office.
Paul has been interested in spirituality and medicine & enjoyed volunteer work in a program that incorporated spirituality in its quest to re-shape lives distorted by drug and alcohol abuse. In addition, he was cofounder of 2 Tulsa area free clinics affiliated with Eastwood and Broken Arrow churches. Paul is married to Julie Cochran and they have 3 grown children.
Sonia Marshall CYT, Relax & Renew® Trainer
Sonia is a Yoga Instructor and Graphic Artist. She earned her 200 hr. YTC in Hatha Yoga from Yoga Spirit Academy in Tulsa, earned a Bachelors Degree in Commercial Art from Oral Roberts University, and in 2015 she was certified as a Relax & Renew@ Trainer in Dallas TX, with Judith Lasater.
She began practicing yoga to manage chronic back pain, stress and anxiety, and through regular practice she discovered how yoga can help to heal the body and mind. From her personal experience, she is inspired and passionate about sharing the practice of yoga with others.
Sonia teaches with a gentle approach, with a focus on body awareness.
Sonia and her husband have been married for 18 years. She has lived in Tulsa for 26 years and enjoys camping with her husband and their two dogs, Stella and Hadi. She loves experimenting with new recipes, traveling, and music.
Ashley Smith is a Licensed Registered Dietitian. She received both her undergraduate and master’s degrees from Oklahoma State University in Stillwater in Nutritional Sciences. She completed her dietetic internship through Oklahoma State, gaining experience in community, management, and clinical settings. Ashley is a member of the Academy of Nutrition and Dietetics.
Ashley is passionate about being able to help people achieve their health and wellness goals. She has a deep desire to help people with food and weight struggles, specifically those with eating disorders and disordered eating. She believes that true freedom and abundant life apart from food is possible. She follows a non-dietiting approach that focuses on intuitive eating and evidence-based nutrition recommendations.
Ashley has been married since May 2014 and enjoys cooking for her husband and friends, being physically active both indoors and out, playing games, and keeping up with her food blog.
Becky Weathers, Office Manager
Becky Weathers is our office Manager. Before coming to Cornerstone, she worked in the health insurance industry for nearly 27 years and then in the medical industry for a little over 3 years. Becky loves working with people and hopes to make a positive difference each day. Becky and her husband Clyde have been married for 25 years and have 3 beautiful daughters. In her spare time, Becky enjoys traveling and spending time with her family.
Deidra Nickel, LPC Candidate
Deidra Nickel earned her M.A. in Marriage and Family Therapy from Southern Nazarene University. She is a registered Licensed Professional Counselor Candidate with the State of Oklahoma.
She has a passion for helping families, especially women, determine who they are in Christ and their purpose as they navigate life’s struggles and hardships.
Deidra enjoys singing at church, spending time with her family and friends, classical music, and riding with her husband on his Harley.
Leanna Harvey, Intern
Leanna Harvey is a graduate student at Southern Nazarene University in Tulsa, Oklahoma. She received her Bachelors of Science Degree in Family Studies and Gerontology in May, 2014 and is pursuing her Masters of Arts Degree in Counseling Psychology, she will graduate in December 2016. She will then work toward obtaining her licensure as a Licensed Professional Counselor. She is a member of the American Counseling Association and the Oklahoma Counseling Association and Oklahoma Christian Counselor Association.
Leanna has a passion to help individuals, couples, and families find meaning in their lives though the transformative knowledge of knowing who they are in Christ and living authentically within their lives. She works in cooperation with her clients and God’s ability within them to experience freedom, purpose, healing, and peace.
Leanna has been married to her best friend, Michael, since 1996. Together they have two beautiful daughters. In her free time she enjoys spending time with her family and friends, playing games, watching football and movies, and reading.
Mary Catherine Corbell, Intern
Mrs. Corbell is originally from south Arkansas and moved to Tulsa after getting married last fall.
She received her Masters in mental health counseling in 2013. Mrs. Corbell has worked in a variety of settings with children and adolescents. Most recently she was in charge of an Integrated Listening Therapy at a Neurodevelopmental Center in Atlanta. She is currently working towards obtaining her LPC certification. Mrs. Corbells passion is to apply her extensive practical therapy and experience to help children and young adults reach their goals.