Family Friendly Mental Health Services

Welcome to Collaborative Care, conveniently located near the Pennybacker Bridge in Austin, TX. Here, our professionals know that mental health is a journey and they're here to help you along the way. We aim to support our patients in a safe and comfortable environment while offering them necessary comprehensive care.

Meet our team.


John Abraham, D.O.

Dr. Abraham is a general, child and adolescent psychiatrist. He completed his undergraduate training in biology at the University of Texas at Austin and completed his medical degree at the University of North Texas Health Science Center at Fort Worth. After medical school, Dr. Abraham returned to Austin and completed residency training in adult psychiatry and a fellowship in child and adolescent psychiatry through The University of Texas Southwestern Medical Center and Seton Family of Hospitals. Dr. Abraham now continues his work at Collaborative Care, where he provides assessment and treatment of children, adolescents, and adults with a variety of behavioral, emotional, social, thought, and autism spectrum disorders. He is committed to providing help to patients and their families affected by mental illness.

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Abby Riggs, RN, PMHNP 

Abby is a family psychiatric nurse practitioner providing psychiatric care and therapy to primarily children and adolescents. She earned her BA in psychology summa cum laude from Southwestern University.  Seeking a career that combined her interests in psychology and biology, she earned her BS in nursing at the University of Texas at Austin.   Before becoming a nurse practitioner, Abby worked at a residential treatment center for children with psychiatric illness. There, she collaborated with an interdisciplinary team of psychiatrists, social workers, nurses, parents, and therapists to develop and implement treatment plans for clients.  That experience confirmed her desire to work as an advanced practice nurse in the area of mental health, and she subsequently earned her Master’s degree in the Psychiatric Nurse Practitioner program at the University of Texas.

When Abby's not working, she enjoy watching movies, cooking, traveling, doing yoga, playing and coaching kickball, and spending time with her family.

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Michael Ross, M.D.  

Dr. Ross is a general and child and adolescent psychiatrist. He completed his undergraduate studies at the University of Michigan in Ann Arbor where he majored in psychology. He then went on to attend medical school at Drexel University College of Medicine in Philadelphia, Pennsylvania. After finishing medical school, he moved to Austin to escape the cold weather and completed both his adult psychiatry residency and then his child and adolescent psychiatry fellowship training at University of Texas- Dell Medical School.

Dr. Ross provides assessment and treatment of children, adolescents, and adults with a wide variety of psychiatric conditions. He has experience working with children and adolescents with prior trauma and has specific interests in managing obsessive compulsive disorder, anxiety disorders, and autism spectrum disorders.

In his free time, Dr. Ross enjoys running, reading, hiking around the Greenbelt, and spending time with family.

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Craig A. Russell, M.Ed, LPC

Craig A. Russell is a Licensed Professional Counselor who has served children, teens, adults, and families for over twenty-five years in his private practice. Prior to opening his therapy practice in 1992, he designed and taught a curriculum of organizational, communication, service learning, and leadership skills for middle school students, served as a middle school counselor, and then was a crisis and substance abuse counselor for a large Austin high school. He has degrees from Baylor University, The University of Texas at Austin, and Texas State University. In addition, he has professional development training and experience in play therapy techniques, grief and loss issues, adoption experience and support, and the use of therapeutic EMDR.

Over the years he has volunteered with teen and children retreats and camps including Hospice Austin’s Camp Braveheart and Mo Ranch’s Ropes Course programs. He has also happily spoken to various groups including teacher in-services, Gladney adoptive parents groups, UT Social Work School classes, and various parenting and school groups as requested.

Craig and his wife, Melissa, a Hospice Austin chaplain, have three sons. He is grateful for their helpful, humbling, and willing participation in his personal growth. As a counselor, he is committed to a caring, supportive, collaborative working relationship with his clients.

Greer Swiatek, LPC, CRC, NCC, NLC-C

Greer Swiatek is a Licensed Psychotherapist who provides counseling services to individuals and families. She utilizes a collective approach in therapy, encouraging people to feel empowered during the therapeutic process and in their everyday lives. Her theoretical orientation is Person-Centered, meaning she promotes growth by harnessing unconditional positive regard, empathic understanding, and a strong therapeutic alliance with her clients. Greer knows that harnessing healthy relationships with others starts with self awareness and the ability to self regulate. She holds space for her clients to get to know themselves better and works with them to find self compassion and healthy coping skills. 

Greer is up to date on the latest neuroscience related to psychology and integrates psychoeducation into her practice. She helps people better understand what is going on in their brain to further increase self awareness. She also helps her clients learn healthy relationship principles which can be applied in any environment. 

Greer earned her Master’s in Rehabilitation Counseling from Georgia State University in Atlanta, Georgia. She earned her Bachelor's of Science in Psychology and Business Management from The University of Tennessee in Knoxville, TN. In addition to seeing clients in the office, Greer provides Equine Assisted Psychotherapy services at a nearby ranch. She is certified in the Natural Lifemanship Model of Trauma Focused Equine Assisted Psychotherapy. Furthermore, Greer works as a trainer for Natural Lifemanship, providing mentorship and training to other mental health professionals. 

In her free time, Greer enjoys traveling, hiking, gardening, and tending to her chickens. 

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Mark Viator, LCSW

Mark Viator is a licensed psychotherapist with more than 20 years experience in adult and adolescent, couples, and family therapy. He also has extensive training in Jungian psychology and dream work. Mark has been in private practice since in Austin 2004 and a partner at Collaborative Care since 2014.

Mark states his purpose as a psychotherapist is to serve individuals, couples, and families with humanistic and accessible therapy that meets their immediate needs and gives them the insight and tools they need for their continued growth. He assesses each client’s individual strengths and challenges, and while moving at a pace comfortable to them, uses the treatment approach that best suits their presenting problems.

Mark’s experience as a clinical social worker and Jungian trained therapist has allowed him to work with people from all sorts of backgrounds. He has worked on several multi-disciplinary teams with psychiatrists, family practice doctors, and other therapists, and his Jungian background has given me many years of experience working with dreams and the unconscious.

Some of the issues Mark has experience working with are:

  • Depression and Anxiety

  • Creativity

  • Grief and Loss

  • Couples/Marital Counseling

  • Autistic Disorders

  • Early Adulthood Transitional Issues

Mark is also a professional guitarist and songwriter who has extensive experience over the course of his life, performing, touring, recording, and producing music. He has written numerous documentary soundtracks, scored theatrical productions, and he continues to write and record constantly. This experience has transferred nicely to his work as a psychotherapist, particularly in working with artists and creative people to achieve their fuller potential.


William C. Streusand, MD

Dr. William Streusand is a child and adolescent psychiatrist who first went into practice in 1985. He currently describes his status as “semi-retired” as he is not engaging in an ongoing private practice at this time. He has experience in complex care and initiating various systems of care models. Current interests and activities include prevention/wellness models, propagating integrated care models, and teaching. He works part time in an integrated care pediatric clinic in Colorado, Pediatric Associates of Durango, at People’s Community Clinic in Austin, and is available for consultations/evaluations/second opinions at Collaborative Care. He does not do legal or custody work. Dr. Streusand was the co-founder of the Texas Child Study Center and was the chief of Psychiatry at Dell Children’s Medical Center for 12 years. He is on the Board of Directors of C2 Change, a sliding scale mental health provider in Austin, and has participated in the Children’s Mental Health Crisis Task Force in Travis County.  


Hayley Kimble, LCSW 

Hayley Kimble is a Licensed Clinical Social Worker.  She graduated from the University of Texas at Austin with a BA in Psychology and a Masters in Social Work.  In the past, she's worked for an Early Intervention Program, counseling young children and families. 

Hayley has experience with Attachment, behavior problems, Autism Spectrum Disorders, the parent/child relationship, working with schools, as well as treating mental, emotional and behavioral issues.  She has also worked in a residential home for children and taught pre-school.  Hayley believes that seeing a child or family in their natural environment can provide helpful insight to treatment and is willing to provide school and home visits when necessary or convenient.  She is passionate about helping children find their strengths and using those to create unique strategies for individual problems. 

Hayley has most recently been home with her two boys, 8 and 6, and she is thrilled to return to practice, working with the team at Collaborative Care and with children and families to find solutions and manage concerns.  Her hope is to provide an environment of compassion and support to help individuals and families overcome obstacles to move forward and thrive.


Katie Costello

Katie joined the Collaborative Care team as Office Manager in June 2019. She graduated from Southwestern University summa cum laude with a Bachelor of Science in Biochemistry. During her time in college, Katie served as member of the Residence Life Staff, a research assistant, and a member of the Southwestern Chorale. Katie is excited to be a part of the Collaborative Care team, hoping to one day become a mental health provider herself.