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Leadership

Our Team

Leadership

  • Steve Zamarripa, MBA
    Steve Zamarripa, MBA
    President & Chief Executive Officer

Executive Team

  • Sharon Volner, LMFT
    Sharon Volner, LMFT
    Chief Clinical Officer
  • Diahann Klein, LMFT
    Diahann Klein, LMFT
    Chief Operating Officer

Medical

  • Dr. Carol Kiriakos, MD
    Dr. Carol Kiriakos, MD
    Medical Director
  • Wendy McCain
    Wendy McCain
    Director of Nursing

Clinical Leadership

  • Gwendolyn Casella
    Gwendolyn Casella
    Director of Detox & CD Programs

Check back soon for a complete list of all Directors and members of our leadership team.

Accreditations & Memberships

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La Ventana  Treatment Programs - Thousand Oaks BBB Business Review

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(800) 560-8518
Steve Zamarripa, MBA
President & Chief Executive Officer

Born and raised in Southern California, Steve earned his BA from USC and his MBA from Columbia University. Steve had launched, grown and sold several highly successful businesses over the years and began to realize what he thought was the American dream – independence and abundance amidst an early retirement. Once that dream materialized Steve became increasingly aware of a profound emptiness and felt something essential in his life was missing. He craved a life of more substance, where he could give back and make a difference, and so began his journey inward in search of meaning and connection.

During his self-reflection, Steve began to gain insight into the profound impact his family of origin experiences had had on his development and, in turn, his ability to have meaningful connections with others. The lives of his father, grandfather and uncles were fraught with alcoholism and addiction and his mother had suffered an eating disorder which contributed to her early death. With his primary caregivers living in the grips of addiction and an eating disorder, Steve was left to fend for himself in a household full of fear and dysfunction. As an adult, despite his best efforts to change the intergenerational patterns of dysfunction that he experienced, Steve saw his own familial relationships continue to suffer. In 2007 Steve had a spiritual awakening when he realized he had been living only as a survivor. This realization in conjunction with inspiration from his personal experiences manifested a desire to create a place to help, a peaceful place for people to heal. La Ventana Treatment Programs became that place: a home for professionals deeply invested in the recovery process, and a place for those suffering from substance abuse and mental health issues to find help and long-term recovery. La Ventana is held up by a stellar staff that carries the same passion for recovery and service that Steve does. With the birth of La Ventana Treatment Programs, Steve has found a way to give back to the world, fulfilling his passion to help others live long and prosperous lives.

Sharon Volner, LMFT
Chief Clinical Officer

My philosophy is that people, whether they are struggling with mental health or addiction issues, need to know their reality.


Sharon brings a broad range of experience to her role as the Chief Clinical Officer of La Ventana Treatment Program. She has over twenty years experience working with at-risk youth, couples, families, and adults in the field of mental health and addiction. She has worked at various rehabilitation centers with youth and adults struggling with issues of addiction and their underlying psychological causes. Sharon has worked as a trainer and operator on a crisis suicide hotline. Sharon has worked directly with the homeless population in assisting them in stabilizing severe and persistent mental health and substance dependence as well as gaining housing and employment. Sharon maintains a private practice in Westlake and is a Clinical Supervisor to registered interns working towards their licensure. Sharon’s approach is multi-modal: she addresses the biological, psychosocial, spiritual, and nutritional aspects of addiction and treatment.

Sharon earned her MS in Counseling with Distinction from California State University. She is a member of CAMFT, and a Co-Leader of her daughter’s Girl Scout Troop in efforts to help young girls develop empowerment and leadership.

Diahann Klein, LMFT
Chief Operating Officer

There is hope. There is help. This is the message I want clients to hear. Our team has a profound understanding of the recovery experience which allows them to deeply hold space between themselves and the client. It is in this very space where clients gain trust and change manifests.


Diahann has held various senior executive clinical and administrative functions and has considerable experience in operating and building behavioral healthcare companies. She is honored to currently serve as COO of La Ventana and work alongside some of the most talented, experienced and passionate staff in the field of mental health and substance use disorders. Diahann has sat on both non-profit and for-profit Boards serving the mental health, substance use, and eating disorder populations since 2008. In her various Board positions she has developed addiction and mental health intervention and awareness campaigns and high-level professional trainings and workshops for practitioners. She is a past Board President of the International Association of Eating Disorder Professionals (IAEDP) and Education Board Chair of the Women’s Association of Addiction Treatment (WAAT). She is a Licensed Marriage and Family Therapist (LMFT) and active member of both the California Association of Marriage and Family Therapists (CAMFT) as well as the Academy of Eating Disorders (AED). She is also certified as an Administrator by the Department of Social Services.

Diahann says, “Witnessing and facilitating the healing process is what drives, inspires, and sustains (her) in every aspect of (her) day-to-day work.” She is passionate about using both evidence-based and practice-based knowledge to provide the highest quality of clinical treatment, grow programs of excellence, and further advance ethical and professional standards in the healthcare industry. Through the lens of a personal story of recovery her plans for La Ventana’s growth and expansion have been in alignment with her understanding of the increasing complexities of care required by addiction and mental health diagnoses. She is committed to increasing integration and coordination of healthcare services to span levels of care, disciplines and professions to achieve healing that is not only sustainable but elevates the individual’s quality of life beyond their baseline. She believes in continual professional growth with the underlying belief that clients never fail but rather our best efforts to assist the clients do and that the greater ‘we’ are ultimately responsible.

Diahann was raised in New York and graduated Cum Laude with a Bachelor’s degree in Political Science from Middlebury College, a Masters degree in Psychologyfrom Antioch University, and a Certificate from the London School of Economics and Political Science.

Dr. Carol Kiriakos, MD
Medical Director

A board certified psychiatrist with over a decade of experience, Dr. Carol Kiriakos is best known to her clients as, “Dr. K.” A warm, passionate, and approachable expert in the field of recovery in various aspects, Dr. Kiriakos comes from a long line of “shrinks.” Her family legacy runs deep in Los Angeles. Her Father is a psychoanalyst, addiction specialist, geriatric specialist and also works with the eating disorder population. Her brother is a cognitive behavioral specialist and works primarily in helping people work through their phobias and anxieties. With this lineage, it is not surprising that Dr. K believes that client-centered work within a multidisciplinary team helps people and benefits the community.

Dr. Kiriakos’ passion lies in working with individuals who struggle with disordered eating, eating disorders, and addiction. She is regarded as a psychiatric expert in addiction, eating disorders, and dual diagnosis in the Los Angeles area and has held roles as Medical Director and Psychiatrist roles within the field. Dr. Kiriakos completed her B.A. in Psychology from the University of California, Los Angeles and went on to earn her M.D. at the Pennsylvania State College of Medicine.

Prior to entering the field of psychiatry, Dr. Kiriakos worked as a Physician Utilization Reviewer for 30 insurance companies throughout the U.S. for 5 years. In her work, she made determinations regarding medical necessity on behalf of insurance companies using approved clinical criteria. Her clinical opinion was sought regarding levels of care, frequency of services, types of care and other modalities of treatment.

In addition to her work in day treatment centers for eating disorders and substance abuse, she has held a private practice psychiatrist in Beverly Hills for over 10 years doing both medication management and therapy covering a wide ranges of diagnoses: addiction, depression, Bipolar Disorder, PTSD, generalized anxiety, Panic Disorder, ADHD, women’s health issues and eating disorders.

Gwendolyn Casella
Director of Detox & CD Programs

“If I can make a difference in one person’s life, restore hope to an addict’s heart, my job is done. One person can make a profound difference.”

Gwendolyn Casella got clean and sober in 1997. She worked at Cri-Help, Inc. for over a decade in a variety of direct care and administrative roles while attending Drug and Alcohol Studies at Pierce and Mission Colleges. Since 2002, Gwen has been tied to the recovery community through her considerable experience as a sober coach and by conducting “extreme interventions” (defined as “recovery by any means necessary”). She has her own business, Recovery Services Unlimited LLC and, notably, was featured on A&E’s “Relapse, the Sober Coach Chronicles.” Identifying integrity as the underpinning of her approach, Gwen considers herself very lucky to be trained by some amazing mentors for whom she has always had a tremendous respect. Having worked at several treatment facilities, Gwen now passionately devotes all of her professional efforts to her role as Director of Detox and CD Services at La Ventana. She believes she was meant to do this work and loves doing it. When Gwen is not working, she spends time with family and sings in her band.