Meet Our Leadership
Our Executive Team is dedicated to providing compassionate, innovative leadership to enhance the well-being of individuals and families in Pomona, Claremont, and La Verne. With a strong commitment to mental health and wellness, we work collaboratively to ensure accessible and equitable behavioral health services for our diverse communities.
Executive Director
Ontson Placide, MA, LMFT
As Executive Director of Tri-City Mental Health Authority (TCMHA), Ontson Placide, LMFT, provides strategic direction, coordination, and oversight for the agency’s comprehensive system of care, ensuring TCMHA continues to meet the evolving behavioral health needs of the community. With over 30 years of comprehensive experience in community behavioral health and social services, Mr. Placide is committed to operational excellence in both public and private/non-profit community agencies. His extensive background includes program development, clinical and administrative operations, and quality assurance development and implementation. Throughout his career, he has been passionate about delivering innovative, best-practice services to unserved and underserved youth, adults and families in the safety net system of care.Mr. Placide has extensive leadership experience prior to TCMHA, including as Chief Program Officer (CPO), where he directed programs focusing on empowering at-risk youth and families through behavioral health and social services. He has managed one of the largest public mental health clinics in Los Angeles County, overseeing clinical operations and service delivery. Additionally, Mr. Placide has held senior leadership roles for one of California's largest behavioral health service providers. He has also led strategic efforts to expand services in response to state reforms, including California's Continuum of Care Reform (CCR) and California Advancing and Innovating Medi-Cal (CalAIM) initiatives.
Mr. Placide earned his Bachelor's degree in Psychology from the University of Nevada, Las Vegas, and a Master's degree in Clinical Counseling Psychology from Pepperdine University. Since 1993, he has been a licensed Marriage and Family Therapist in the State of California. Mr. Placide actively participates in numerous community and county advisory councils, advocating for the well-being of adults, youth, and families.
Medical Director
Seeyam Teimoori, MD
Dr. Seeyam Teimoori, MD, oversees TCMHA clinical and medical operations, including medication support and psychiatric care and brings over 29 years of experience in Family Medicine, Psychiatry, and Addiction Medicine. His leadership at TCMHA is focused on enhancing care coordination and promoting collaborative healthcare models. He is dedicated to enhancing access to mental health and co-occurring substance use treatment services, with a strong emphasis on integrated and whole-person care that addresses the full spectrum of behavioral health needs.Dr. Teimoori earned his MD from Shiraz University of Medical Sciences. He completed a combined residency in Medicine and Psychiatry at the University of Pittsburgh Medical Center, where he served as chief resident and was actively involved in the Assertive Community Treatment (ACT) program. He is board-certified by the American Board of Addiction Medicine, the American Board of Family Medicine, and the American Board of Psychiatry & Neurology.
Concurrent with his role as Medical Director, Dr. Teimoori also serves as an Assistant Professor of Psychiatry and Family Medicine at Western University of Health Sciences. He is an active member of numerous prestigious professional organizations, including the American Academy of Family Physicians (AAFP) and the American Psychiatric Association (APA).
Chief Clinical Officer
Elizabeth Rentería, LCSW
Elizabeth Rentería, LCSW, oversees all TCMHA clinical services and leads the development and implementation of new standards and services to ensure the delivery of the highest quality of behavioral health care. With extensive experience in direct care, her clinical philosophy emphasizes a client-centered approach, integrating strength-based and culturally relevant practices to support healing and growth. Alongside her Chief Clinical Officer role, Ms. Rentería is also a part-time lecturer at California State University, Fullerton.Prior to joining TCMHA, Ms. Rentería was a clinical program manager for a county behavioral health provider where she oversaw comprehensive care for children, youth, and families. She has a strong background in systems of care, mental health, equity, diversity, and program development, and has presented at both local and national conferences on these topics, including the National Council of Behavioral Health and the Southern California Association for Healthcare Risk Management.
Ms. Rentería received her Master’s in Social Work from the University of Washington School of Social Work and a Master’s in Counselor Education/School Counseling and Guidance Services from the University of La Verne.
Chief Financial Officer
Diana Acosta, CPA
Diana Acosta, CPA, serves as the Chief Financial Officer (CFO) at TCMHA, where she oversees the financial management and strategic fiscal direction of the agency. With over 30 years of experience in financial leadership within public finance, Ms. Acosta is responsible for managing the agency’s budget, implementing effective and efficient strategies to maintain fiscal stability, and ensuring compliance with county, state, and federal regulations. In her current leadership role, Ms. Acosta ensures the responsible stewardship of the Mental Health Services Act (MHSA) funding, supporting the expansion and sustainability of behavioral health services for the community.Prior to joining TCMHA, she held the position of audit manager for a CPA firm where she gained extensive experience in public finance and government accounting. She was responsible for the planning and completion of financial and federal compliance audit engagements for various governmental entities and was also responsible for the preparation of complex financial statements.
Ms. Acosta holds a bachelor's degree in Public Administration with a concentration in Accounting, is a Certified Public Accountant and is a member of the California Society of Municipal Finance Officers (CSMFO), and the Government Finance Officers Association (GFOA).
Chief Compliance Officer
Natalie Majors-Stewart, LCSW
Natalie Majors, LCSW, serves as the Chief Compliance Officer (CCO) and director the Best Practices Division at TCMHA. With over 20 years of experience in community mental health, in both direct care and quality management, she is dedicated to fostering a culture of ethics, compliance, and continuous quality improvement. Ms. Majors is responsible for ensuring the agency’s compliance with all applicable local, state, and federal laws and regulations, engaging and pro-actively supporting all levels of leadership and staff.Ms. Majors has a proven track record of success in driving initiatives that enforce both quality care and compliance, as well as ensuring that behavioral health organizations meet their legal and ethical obligations. Prior to her executive role, she served in other quality assurance and improvement leadership positions where she was instrumental in developing the foundation of the Best Practices Division.
She is deeply committed to supporting a comprehensive system of care where compliance and quality are central to delivering effective and client-focused behavioral health services.
Director of Mental Health Services Act (MHSA) and Ethnic Services
Dana Barford
Dana Barford oversees all TCMHA non-clinical MHSA programs and ensures agency compliance with the MHSA regulations. Her responsibilities include fostering effective and sustained engagement of community stakeholders, developing culturally appropriate and community-driven programming, tracking and reporting quality improvement data, and preparing annual reports for state agencies. She also serves as an alternate for TCMHA on the California Mental Health Services Authority (CalMHSA) Board of Directors.Prior to this role, Ms. Barford was the MHSA Projects Manager at TCMHA. Since 2009, Ms. Barford has been instrumental in the development, implementation, and oversight of numerous MHSA-funded programs at TCMHA, with a focus on prevention and early intervention and innovative projects that support the recovery of individuals with behavioral health needs. She has played a prominent role in stakeholder engagement throughout the annual community program planning process and has overseen the development of the Cultural Competence Plan, as well as the MHSA Three-Year Program and Expenditure Plan and its Annual Updates.
She holds a degree in Special Education from the University of Nevada Las Vegas. Before TCMHA, she held leadership positions at a therapeutic educational services provider for youth and their families, focusing on parent support and call center operations. Earlier in her career, Ms. Barford worked as a special education teacher.
Human Resources Director
Kitha Torregano
With over 20 years of experience in public sector human resources, Kitha Torregano is responsible for overseeing TCMHA's HR operations, including employee relations, recruitment and selection, leaves and benefits administration, workers' compensation, and classification and compensation.Ms. Torregano earned a bachelor’s degree in Business Administration with a focus on Human Resources Management and English from the University of California, Riverside. Before joining TCMHA, she held key HR positions at several prominent public sector organizations, where she led human resources initiatives and supported organizational development across various government agencies. Throughout her career, she has developed a well-rounded expertise in all aspects of human resources, particularly in employee relations, negotiations, and the administration of various HR functions within the public sector. She is trained and certified in various aspects of HR including ADA/FEHA Compliance, Public Policy and Ergonomics.
Ms. Torregano is passionate about public sector human resources, ensuring public agencies remain as competitive as possible with their private-sector counterparts, and driving organizational success through effective, diverse, equitable, inclusive and accessible HR management.
Controller
Trevor Bogle
As Controller, Trevor Bogle ensures TCMHA fiscal responsibility, transparency, and adherence to public sector financial regulations. He is a seasoned financial leader with extensive experience in governmental accounting, financial oversight, and regulatory compliance.With 17 years of experience, Mr. Bogle specializes in implementing and maintaining robust internal control systems and financial environments that promote accountability and efficiency in government-funded programs. He has successfully led initiatives to enhance budget management, optimize grant and fund utilization, and ensure compliance with state and federal regulations. Prior to joining TCMHA, he served as a senior analyst at a public utilities agency, and as an audit supervisor at a CPA firm, where he drafted and oversaw the independent financial statement audits of various municipalities across the state of California, including special districts, cities and counties.
Mr. Bogle holds a bachelor's degree in Public Administration with a concentration in Accounting from California State University, San Bernardino. Committed to financial stewardship in the public sector, he is dedicated to aligning fiscal management with the organization’s mission to deliver accessible and effective mental health services to the community.