Meet our Team

Our Psychiatrist / Addictionologist

Dr. Muhannad Kassawat

Psychiatrist/Addictionologist/Medical Director
Dr. Muhannad Kassawat is a Psychiatrist and Addictionologist certified with the American Board of Psychiatry and Neurology, as well as with the American Board of Addiction Medicine.  He received his medical degree from the Superior Institute of Medical Sciences in Havana, Cuba in 1992. He then went on to earn his master’s degree in biology from Youngstown State University in 2001, as well as his Ph.D. in cellular and molecular biology from Kent State University in 2006.  Since that time, Dr. Kassawat has served as Medical Director for The United States Air Force Base in Eglin, Florida, Medical Director for Trumbull Memorial Hospital in Warren, Ohio, as well as Chief of Psychiatry for Mercy Health-St. Elizabeth Hospital in Youngstown, Ohio. 
Dr. Kassawat then founded The Serenity Center of Youngstown, LLC, in 2015, where he serves as Owner and Medical Director. Under his guidance, The Serenity Center has grown into a
successful 3-location practice where children, adolescents, and adults are treated for a wide variety of presenting mental health and substance abuse problems.  In 2020, Dr. Kassawat’s passion for quality mental health and addiction practices inspired him to found Florida Psychiatric Services, where he devotes his professional efforts to providing the highest level of care.  Dr. Kassawat is also currently on staff at Port St. Lucie Hospital in Port St. Lucie, Florida, and The Vines Hospital in Ocala, Florida providing adult inpatient psychiatric treatment.

Administrative Staff

Wendy Metheny

Chief Operating Officer

Wendy Metheny holds the position of Chief Operating Officer. In this role Wendy works to advance The Serenity Center of Youngstown’s mission, core values, strategic priorities, and growth goals.  She achieves this by implementing programs, processes, and practices that drive the company culture to ensure all services are delivered in an efficient, compliant, and effective manner.

Wendy brings more than 20 years of experience in business management and administration and fosters a team-based, collaborative approach to leadership. 

Wendy currently oversees the operations of Serenity’s three locations and 30+ employees.  She also serves as the human resource administrator as well as managing marketing development.

Rachel Chmielewski

LISW-S, Clinical Director

Rachel holds the position of Clinical Director/AoD Program Director here at Serenity Center. She brings more than 15 years of experience working in the mental health and addiction treatment fields to her position, through which she oversees all operations and clinical staff within both the mental health and addiction treatment programs for all three locations while also maintaining a small caseload of counseling clients. Rachel graduated with her Bachelor of Science in Child & Family Studies from Ohio University, and with her Master of Social Work from The University of North Carolina at Wilmington. She is licensed in the State of Ohio as a Licensed Independent Social Worker-Supervision Designation. 

Her previous work experience includes having worked in the private sector of outpatient mental health counseling as well as with Veterans, active-duty service members, and their families through her time as a Clinical Social Worker for the Department of Defense, and with the Veterans Health Administration at the San Diego VA Medical Center. During her time at the V.A.M.C she worked in both inpatient and outpatient Mental Health and Alcohol & Drug Treatment Programs treating mental health and dual diagnosis populations, collaborating to help create a specialized program for treatment of co-occurring Post Traumatic Stress Disorder and substance use disorders.  

Rachel specializes in assessment & diagnosis, professional development/supervision, and in the treatment of Anxiety, Post-Traumatic Stress Disorder/Trauma, Depression, Marital/Relationship conflicts, and Dual Diagnosis & Substance Use Disorders.  

Michelle Griffin

Administrative Director & Client's Right Officer

Michelle holds both the role of Administrative Director and Clients Rights Officer here at Serenity Center of Youngstown. She brings 12 years of Customer Service experience and almost 20 years of Business Administration/Management experience to her positions, through which she oversees all administrative and ancillary staff in all three of our locations. As part of the dedicated team of management staff, she works to help ensure the agency maintains its high standards of compliance and quality service delivery, as well as advocating on behalf of all clients to help ensure their needs and expectations are met.  

Therapists & Counselors

Marisa Mook

Marisa is a Licensed Independent Social Worker with Supervision designation who graduated with a Master’s Degree from Youngstown State University in 2012. She has been with Serenity Center since 2018, working as an Outpatient Therapist Supervisor.
Marisa’s experience includes working with children and families in home-based therapy settings, residential facilities, and school-based environments. Her practice has allowed her to provide clinical mental health services to a wide range of populations that age from toddlers to geriatrics, including drug and alcohol treatment for adults. She has provided care in individual and group settings, as well as through program development.
Marisa has worked extensively with Positive Behavior Intervention Supports (PBIS), crisis intervention, and trauma-informed care. She is currently in the process of obtaining Eye Movement Desensitization and Reprocessing (EMDR) certification and is excited she will be offering this form of therapy soon.

Catina Taylor


Tina graduated with a Bachelors in Psychology and a Masters in Social Work from THE Ohio State University.

For close to 25 years Tina has been fortunate to have been able to continue to work/practice in a variety of settings. She practiced in Columbus for over half of those 25 years where she worked in adolescent residential treatment, administration and supervision in HIV/AIDS, rural outpatient mental health therapy/counseling, and as an emergency department social worker. Having grown up in the tri-county area, home called her back where she was able to broaden her horizons working as a therapist/counselor for inpatient rehabilitation, along with providing outpatient therapy/counseling.

Tina’s passion is for providing therapy/counseling to adults ages 18 and up. She recently became an ACT therapist and now utilizes acceptance and commitment therapy (ACT) as her sole treatment modality, as it has been scientifically studied and shown to be applicable in a wide variety of conditions.

After nearly 25 years of practice, she continues to have a passion for providing therapy/counseling.  Tina says, “Watching people have success is amazing!” and “It’s such an honor to watch someone become comfortable in a session and be vulnerable with sharing their journey.” “This is what keeps this my passion after almost 25 years!”

Nicholas Taylor


Nick is a 2015 graduate of Penn State-Shenango in Human Development and family studies. In 2017 he became a graduate of Youngstown State University with a Masters of Social Work. In 2020 he earned his Independent License in Social Work. He works with clients of all ages.

Alexander Marosy

Alex has a Bachelor’s Degree in Human Development and Family Studies from Pennsylvania State University and a Master’s Degree in Social Work from Youngstown State University. He is a Licensed Independent Social Worker in the state of Ohio and has been providing counseling services since 2015 and practicing as a social worker at The Serenity Center since 2017.
Alex specializes in mood disorders, depression, anxiety, ADHD, PTSD, substance abuse disorders, and adjustment-related concerns. He enjoys helping his clients overcome difficulties and finds passion in helping them achieve the goals they have set for themselves. He is certified in motivational interviewing and enjoys helping children through play therapy.

Amanda Winkler


Amanda graduated from Youngstown State University with her Masterʻs Degree in Social Work in 2018 and her Bachelorʻs Degree in Social Work in 2015. She is a Licensed Independent Social Worker with Supervisory Designation with professional experience working with both juvenile and adult clients in a variety of settings.

Amanda is a humanistic clinician who specializes in a person-centered approach that combines elements of cognitive-behavioral and solution-focused therapies. Using these therapeutic techniques, she aims to provide support and validation, build upon strengths, collaborate with clients to set attainable goals, and meet client needs.

James Baluck


Jim completed his Bachelor of Science in Psychology and Master of Social Work at Youngstown State University and is currently a Licensed Independent Social Worker (LISW). He has been providing therapy services at the Serenity Center since 2017 and provides both individual and relationship/marriage counseling. Jim works with both adolescents and adults; assisting them in connecting to existing strengths and developing additional skills to support progress toward their mental health goals. Some of Jim’s clinical areas of focus are depression, anxiety, substance-related disorders, and adjustment disorders. 

Pamela Waddell


Bio coming soon …

Vilmary Kausits


Bio coming soon …

Medical Staff

Lauren Miller

Lauren Miller PMHNP-BC is a Psychiatric Mental Health Nurse Practitioner. She graduated from Youngstown State University with a Bachelor’s of Science in Nursing in 2016 and went on to care for patients as a registered nurse in the areas of critical care and inpatient behavioral health before working as a nurse educator providing health education to individuals and groups in inpatient addiction treatment. Lauren graduated from Kent State University in 2020 with a Master’s of Science in Nursing and is a board-certified Psychiatric Mental Health Nurse Practitioner providing mental health treatment to both adults and children.

Kimberly Szabo


Kimberly Szabo is a nurse practitioner with a background in behavioral health and addiction medicine. She graduated from Youngstown State University with a Bachelors in Nursing in 2010 and from Chamberlain College of Nursing in 2016 with a Master’s in Nursing degree. Kim worked as an RN for Mercy Health from 2007 until 2018. After earning her Nurse Practitioner license, she worked under the tutelage of Dr. Kassawat on the psychiatric floor of Mercy Health gaining the experience and knowledge that brings her to her current position as a prescriber at The Serenity Center.

Kristin Tatarka


Kristin Tatarka is a Board-Certified Family Nurse Practitioner. She graduated from Youngstown State University in 2006 with a Bachelor of Science in Nursing. She started her RN career in a hospital Intensive Care Unit, and then went on to a career in Correctional Nursing from 2007-2015. She graduated from Youngstown State University in 2013 with a Master of Science in Nursing with an Adult Clinical Nurse Specialist focus, and again graduated from YSU in 2015 with a Post-Master’s Certification as a Family Nurse Practitioner. She holds a national board certification with the American Nurses Credentialing Center (ANCC) as a Family Nurse Practioner. 

Kristin started her Nurse Practioner career working in a private family practice office, and then went on to work as an Advanced Certified Hospice and Palliative Nurse Practioner (ACHPN) from 2016-2019. 

Kristin ultimately achieved her professional goal of working in the Mental Heath field at The Serenity Center of Youngstown in 2019.  She most recently graduated from Ursuline College in 2021 with a Post-Master’s Certification for a Psychiatric Mental Health Nurse Practioner. 

Kristin currently works as a Nurse Practitioner at The Serenity Center where she provides a compassionate and patient-centered approach to those needing mental health and addiction medication-assisted services.

Renee L. McManus


Bio coming soon…

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