OUR TEAM
Meet Our Team
Marcy Gunn, Psy.D.
Owner/Director of Child Psychology
Dr. Gunn is a licensed clinical psychologist who sees individuals of all ages. Having begun with a particular interest in working with children, adolescents and families, she now enjoys seeing clients across the lifespan. She has over thirty years of experience in the Dayton area providing therapy and assessments for a diverse range of needs, and she has been the owner of Cordell Associates, LLC for the past seven years. Areas of expertise include treatment of childhood sexual abuse and other traumas; interventions with children who have experienced family disruptions such as divorce and/or foster or kinship care placement; assisting individuals on the autism spectrum and their families; and helping adult women cope through life’s transitions. Dr. Gunn also provides clinical supervision to several of the psychology residents and psychology assistants in the office.
Jonathan Cleveland, Ph.D.
Director of Adult Psychology
Dr. Cleveland (Jon) meets with adults who experienced difficult childhoods. Over the course of treatment, he collaborates to boost insight, self-esteem, resiliency, flexibility, the ability to trust, as well as the capacity for humor and creative expression. Jon specializes in treating trauma and dissociation using psychodynamic psychotherapy, hypnosis, havening, and EMDR (eye-movement desensitization and reprocessing). For those wishing to focus on parts work, he incorporates ego state and IFS (internal family systems) techniques. He often meets with therapists who are seeking their own psychotherapy or professional consultation and enjoys supervising doctoral students and postdoctoral trainees.
Jon serves as vice president (2025-2027) of the International Society for the Study of Trauma and Dissociation and is founder of the nonprofit organization, Collective Within. He is a clinical faculty member at WSU’s School of Professional Psychology, former editor-in-chief of Trauma Psychology News, and current editor of The Miami Valley Psychologist. In his leisure time, Jon finds himself cooking, reading, and tinkering with synthesizers. He also enjoys playing golf and traveling to new places to ski & scuba dive with friends.
Chelsae Pistello, Psy.D.
Clinical Psychologist
Dr. Pistello is a licensed clinical psychologist who offers therapeutic services and psychological assessment with Cordell Associates. Her clinical interests include holistic and interdisciplinary models of health, mental health education and advocacy, and process based therapies (including ACT and CBT).
As a psychologist, Dr. P has worked alongside people navigating a wide range of clinical concerns- from short term stressors and life transitions to those facing long standing relationship problems and/or severe mental illness. In each case, she strives to create a warm, authentic and collaborative relationship that allows clients to gain insight and make changes relevant to their unique goals. Her aim in each client interaction is to facilitate growth, healing, and wholeness
Erika Fontana, M.S.W., LISW-S
Clinical Supervisor
Erika earned her Master of social work degree from the University of Utah and has been a practicing therapist for over 17 years, with much of her focus on clients with trauma and substance abuse issues. She has received training in EMDR, havening, DBT, and seeking safety, and employs these and other treatment modalities including CBT and mindfulness training according to each client’s needs. She has experience working with adults, teens, children, groups, couples and families, and currently works with both adults and adolescents.
Areas of focus: Trauma, mood disorders, anxiety, grief and loss, substance abuse, relationship difficulties, communication skills, parenting skills
Stephen Hamilton, Ph.D. M.Div.,
Lt.Col. (ret)
Clinical Psychologist
Dr. Hamilton has been practicing with Cordell Associates since 2022. Prior to coming to the practice, he was a staff psychologist at Wright Patterson AFB mental health clinic and faculty member at their APA accredited psychology internship program. Originally from Southern California, he has a combined 32 years of clinical experience, both on active duty and following his retirement, as a civilian psychologist at the Dayton VA and WPat MH clinic. He has been trained in and practiced all the current evidence-based trauma treatments (CPT, PE, EMDR), but has found using the Havening techniques (a new and powerful therapeutic tool to help people recover from painful thoughts, memories, feelings and sensations) to be exceptionally effective. Dr. Hamilton is one of the first certified Havening practitioners and the only trainer in Ohio.
Given his career experiences, he likes working with military members and their families, veterans, first responders, performers, and athletes who seek to perform at a consistently high level under the most challenging conditions and succeed. His clinical interests are sports and performance psychology, anxiety disorders, behavioral health and positive psychology.
Kathryn Strieff, M.S.W., LISW-S
Independent Social Worker
Kathryn has experience and training in a variety of therapeutic approaches, including eye movement desensitization and reprocessing; dialectical behavior therapy; mindfulness; motivational interviewing; cognitive behavioral therapy; and problem solving therapy. To learn more about her philosophy and approach, you mayvisit www.KathrynLStreiff.com
Donna Tromski-
Klingshirn, Ph.D., LPCC-S
Clinical Counselor
Dr. Donna Tromski-Klingshirn is a Licensed Professional Clinical Counselor-Supervising Counselor (LPCC-S) with a PhD in Counselor Education & Supervision, a masters degree in counseling (counseling in business and industry concentration), and post-masters clinical counseling coursework from the Ohio University (Athens, Ohio). Before 23 years as a counselor educator/supervisor and faculty advisor for a graduate clinical mental health counseling program (2000-2023), Donna's clinical experience included providing employee assistance and clinical treatment to a wide variety of clients within interdisciplinary contexts and community settings in southeastern and central Ohio. Donna especially enjoys working with clinical teams and students to develop comprehensive service plans tailored to each client’s organic-medical, psychological, systemic-relational, and contextual issues and needs, using a strengths-based, empowerment approach. Dr. Donna is a Lifetime Member of the Chi Sigma Iota Counseling International Honor Society, among other professional memberships, and has served as President of the Ohio Mental Health Counselors Association.
An unapologetic 1970s/1980s throw-back, Dr. Donna especially enjoys music. . . listening, dancing, and swimming to it, as well as playing acoustic guitar and singing. She believes it’s often the best therapy too! She and her husband enjoy live concerts, live sporting events with family and friends, and touring major league ballparks. Since the pandemic, reading audiobooks (non-fiction, self-help) has become her newer habit, especially while taking long walks, working out at home, or road-tripping.
Sherry West
Office Manager
Sherry West has been the office manager at Cordell Associates since 2013. A native to the area, she attended Beavercreek High school and graduated from Greene County Career Center’s medical/legal program. In her role at Cordell Associates, she oversees the front office, from coordinating staff and clinicians, to scheduling new and existing clients, managing payroll to creating quarterly stat reports. She also oversees the credentialing process and much more. In her spare time, Sherry enjoys being with her husband, Greg, and their 12 grandchildren in the outdoors, from gardening to hiking.
Erika Slifer, Psy.D.
Postdoctoral Resident
Erika is a postdoctoral resident currently who earned her doctorate in clinical psychology from Wright State University School of Professional Psychology. Originally from Indiana, Erika earned her master’s degree in mental health counseling (with a concentration in children, adolescents, and families) from the University of Indianapolis and her bachelor’s degree in psychology from Hanover College. She has experience utilizing various psychotherapeutic modalities (humanistic, CBT, DBT, and ACT) and working in community mental health, inpatient and integrated care, and crisis unit settings.
Erika strives to create a safe space for her clients. She enjoys working with all ages, especially teenagers. Her clinical interests include depression, anxiety, trauma, cultural concerns, and disability/chronic illness. Outside of work, Erika loves spending time with her family, watching sporting events (go Bengals!), playing board games, and crafting. She also loves cats, chocolate, and collecting souvenirs.
Misty Brown, M.S.W., L.S.W.
Social Work Trainee
Misty brings with her 39 years of experience as a holistic wellness practitioner who integrates traditional therapeutic modalities with sound of vibrational therapy, somatic therapy and therapeutic art. She is in the process of completing her master’s degree in social work. Misty founded and operates Love Shack (offering free wellness and counseling services) and is known for her work as a community wellness advocate, connecting at risk communities in the Dayton area with services, education and resources since the tornadoes of 2019.
Aaron Edwards, Psy.D.
Postdoctoral Resident
Aaron is from Springfield, Ohio and graduated from Wright State University’s School of Professional Psychology in July 2024 with a doctorate in clinical psychology. He previously trained in university assessment services, private practice, and health clinic settings. He works to help individuals and couples with an integration of person-centered, psychodynamic, existential, and social-justice oriented approaches with an emphasis in medical disability, neurodiversity (ADHD/Autism), and LGBT+ concerns. Continued goals include connecting people to public resources and communities, as well as serving individuals from adolescence to late adulthood. Public service has been a persistent part of his experience, from volunteer event coordination to co-hosting Breaking Silences accessibility support meetings during the pandemic. He has a strong relationship with music, writing, photography, and wildlife.
Alyssa Allen, Psy.M.
Psychology Assistant
Alyssa Allen is a 4th year psychological trainee at Wright State University School of Professional Psychology. She received her bachelor's degree in psychology with two minors in French and Deaf Studies at West Chester University of Pennsylvania. Alyssa's clinical interests include individual therapy, family therapy, group therapy, and assessment with children and adolescents. She is interested in working with children and adolescents with mood disorders, anxiety disorders, ADHD, OCD, disordered eating/eating disorders, trauma, parent-child relational difficulties, and suicidal spectrum behaviors (e.g., suicidal ideations, self-harm, etc.). Alyssa practices from an integrated approach, using DBT, CBT, and ACT modalities to tailor treatment to her clients' specific needs and concerns. Alyssa also fosters cultural humility in her approach to treatment and assessment of diverse communities. Alyssa's research interests include emotion regulation/dysregulation in children and adolescents, parent training, and prevention and intervention of suicidal spectrum behaviors. She previously worked at the Cincinnati Center for DBT where she was extensively trained in DBT and provided comprehensive DBT treatment to adolescents and young adults. Last year, she worked at Cincinnati Children's Hospital Center for ADHD conducting ADHD evaluations for children and adolescents as well as running behavioral parent training and academic success groups. In her personal time, Alyssa enjoys spending time with her cat, Pete, cooking, baking, dancing, watching movies/tv, and spending time with her friends and family.
Aroosa Syed, Psy.D.
Postdoctoral Resident
Aroosa is a graduate of Wright State University’s School of Professional Psychology. She received her doctorate in Clinical Psychology from Wright State University and her master’s degree in educational psychology from University at Albany. She received her bachelor’s degree in psychology from Buffalo State College. Her clinical interests include trauma, anxiety, depression, family/parenting, multicultural identity formation and assessment. She has been a trainee at Resilient Young Ladies and Gentlemen(RYLM), and Child Focus where she worked with young adults and provided individual and group therapy. Aroosa is skilled in cognitive, academic achievement, and personality assessments for both adults and children. Her research interests include emotion dysregulation in adolescents and different issues related to discrimination and racism. She typically takes a cognitive behavioral and feminist psychology approach to treatment. She has been enjoying working in private practice where she has been able to form meaningful connections and further develop her clinical abilities.
Elizabeth Thomsen, Psy.M.
Psychology Assistant
Liz is a third year Psychology Trainee at Wright State University’s School of Professional Psychology. Her professional interests include psychological assessment and psychotherapy with youths and adults. Her clinical interests include learning disorders, ADHD, academic struggles, anxiety, depression, and trauma. Liz works from a person-centered lens that incorporates a social-cognitive perspective and is passionate about helping people connect with their personal strengths and gaining trust in themselves.
Prior to pursuing her doctoral degree, Liz lived in Portland, Oregon where she earned her Bachelor of Science in psychology at Portland State University. She served her Pacific Northwest community through community mental health and crisis work, while also contributing to and leading research projects at the Center for ADHD Research at Oregon Health and Science University. Liz loves being outdoors and spending time with friends and family. She spends her free time skateboarding, swimming, camping, and hiking.
Alana Holsapple, Psy.M.
Psychology Assistant
Alana Holsapple is a 3rd year Psychology Trainee at Wright State University School of Professional Psychology. She received her bachelor’s degree at Bluffton University, where she also played NCAA volleyball. Alana’s clinical interests include therapy and assessment with children and adolescents with anxiety disorders, OCD, grief, and trauma. Her continued goals are to learn and utilize a variety of measures of assessment for diverse populations and implement play therapy techniques into treatment. She works from an integrated CBT, ACT, and strength-based lens to encourage acceptance and empowerment among clients. She previously worked at Dayton Job Corps where she practiced short-term therapy for adolescents and young adults on center. In her free time, Alana likes to listen to music, cook new foods, bike, play volleyball, and go on walks with her dog, Lily.
Alexandria Putney
Billing Assistant
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Ray Oakes, M.A., LPCC-S
Clinical Supervisor
A Dayton resident since 1976, Ray has been affiliated with the practice since 1992. He has worked in partial hospital, intensive residential, outpatient and school settings with a primary focus on children, parenting & family. Consulting with school personnel to support achievement has been a major focus. Family, friends, exercise & social justice are passions that give purpose.
Marcus Haase, Psy.M.
Psychology Assistant
Marcus Haase is a 4th-year Psychology Trainee at Wright State University School of Professional Psychology. He received his bachelor’s degree at Kent State University, where he wrote a senior honors thesis on using linguistic analysis to detect anxiety and depression. Marcus’s clinical interests include therapy with and assessment of adults with depression, anxiety, ADHD, and trauma. He is looking to get more experience working with couples and families, as well as becoming proficient in a broad range of psychological assessments. He works primarily from a Humanistic/Existential lens, integrating CBT, ACT, and more to meet clients where they're at and make sure their needs are at the center of his clinical work. He previously worked at Dayton Job Corps and South Community, Inc., where he practiced a variety of techniques and approaches while working with clients ranging from mid-adolescence to later adulthood to address a wide range of presenting problems. In his free time, Marcus likes to watch movies, cook new recipes, and maintain his thriving Lego collection.
Liz Thomsen, Psy.M.
Psychology Assistant
Liz is a fourth year Psychology Trainee at Wright State University’s School of Professional Psychology. Her professional interests include psychological assessment and psychotherapy with youths and adults. Her clinical interests include learning disorders, ADHD, academic struggles, anxiety, depression, and trauma. Liz works from a person-centered lens that incorporates a social-cognitive perspective and is passionate about helping people connect with their personal strengths and gaining trust in themselves.
Prior to pursuing her doctoral degree, Liz lived in Portland, Oregon where she earned her Bachelor of Science in Psychology at Portland State University. She served her pacific northwest community through community mental health and crisis work, while also contributing to and leading research projects at the Center for ADHD Research at Oregon Health and Science University. Liz loves being outdoors and spending time with friends and family. She spends her free time skateboarding, swimming, camping, and hiking.
Alana Holsapple, Psy.M.
Psychology Assistant
Alana Holsapple is a 4th year Psychology Trainee at Wright State University School of Professional Psychology. She received her bachelor’s degree at Bluffton University, where she also played NCAA volleyball. Alana’s clinical interests include therapy and assessment with children and adolescents with anxiety disorders, OCD, grief, and trauma. Her continued goals are to learn and utilize a variety of measures of assessment for diverse populations and implement play therapy techniques into treatment. She works from an integrated CBT, ACT, and strength-based lens to encourage acceptance and empowerment among clients. She previously worked at Dayton Job Corps where she practiced short-term therapy for adolescents and young adults on center. In her free time, Alana likes to listen to music, cook new foods, bike, play volleyball, and go on walks with her dog, Lily.
Alyssa Bolander, Psy.M.
Psychology Assistant
Alyssa Bolander is a 3rd year Psychology Trainee at Wright State University School of Professional Psychology with a focus on childhood. Alyssa also received her bachelor’s degree at Wright State University in Psychology with a clinical concentration. Her clinical interests include therapy and assessment with children and adolescents predominantly with ADHD and familial/relational dynamics. Additional areas of interest for Alyssa include anxiety disorders, OCD and grief work. Alyssa’s continued goals are to learn and utilize a variety of measures of assessment and therapy with children and adolescents within diverse populations. Alyssa uses an integrative approach to treatment with a basis in client centered theory and feminist theory. This allows her to encourage acceptance and empowerment among clients to meet their unique, individual needs while simultaneously incorporating other evidence-based approaches to collaboratively work with clients to meet their goals. Her previous work was at Miami University where she practiced short-term therapy for young adults who predominantly presented with ADHD, anxiety, depression, and relational concerns. In her free time, Alyssa likes to cook new foods, hang out with friends and family, and spend time outside.
