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Dr. Petra Gyles 

Registered Psychologist, Clinic Owner

Dr. Petra Gyles, C. Psych is a Clinical & School Psychologist specializing in child and adolescent populations.  

Dr. Petra Gyles Child Psychologist Barrie

She completed her Ph.D. at McGill University.  Dr. Gyles has 15 years experience working in various school systems, as well as work experience in clinical/rehabilitation outpatient and private practice settings in Toronto, Montreal,  and remote rural and First Nations communities.  


Her research and publications have examined inquiry-based learning, giftedness, resilience, intrinsic motivation, and specifically ‘Growth Mindsets’.  She has shared her research contributions at conferences across Canada and North America.  Dr. Gyles has taught graduate and undergraduate courses at various post-secondary institutions including the University of Toronto, McGill University, and Seneca College.

Dr. Gyles is a Registered Member with the College of Psychologists of Ontario.  

Mikayla Jeffery

Registered Psychotherapist (Qualifying) & Psychometrist


Mikayla is a Psychometrist & Registered Psychotherapist (Qualifying). She completed an MA in Counselling Psychology at Yorkville University, an MA in Education Studies with a focus on School & Applied Child Psychology at Western University, as well as a BA Honours in Psychology and a BEd at Nipissing University. She is currently a member in good standing with the Ontario College of Teachers (OCT).

Mikayla has experience working in a wide range of settings to support children, youth, young adults, and their families as well as 4 years of experience administering psychological and educational assessments in pediatric and private practice settings in Ontario.  She brings skills and experience in instruction, intervention, research & statistics, and multi-disciplinary consultation. She values meeting clients where they are at and working collaboratively with them and their families to help them reach their full potential.

Karen Kumar


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Karen Kumar is a second year Clinical Psychology MA student at Toronto Metropolitan University (formerly Ryerson) and will be beginning her PhD fall 2024. She also earned a Master of Education in Developmental Psychology at The Ontario Institute of Studies in Education, University of Toronto. Karen has worked extensively with children and adolescents with diverse developmental and learning needs across various settings, including research and academic settings. More recently, she has expanded her clinical training in assessment and psychotherapy for adults. At the clinic, Karen works collaboratively to provide comprehensive psychoeducational and mental health assessments to children and adolescents.

Sevval Cinar


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Sevval completed her undergraduate degree in Health Sciences at Wilfrid Laurier University and minored in Biology and Psychology. She is currently a second year Developmental Psychology Master's student at Wilfrid Laurier University.


Sevval’s research interests lie mainly in social emotional learning and development of young children. In addition to her academic pursuits, Sevval has been working as a psychometrist with preschool and school-aged children and adolescents with neurodiversity along with learning & mental health differences and challenges. Sevval is passionate about continuing to work with children, their families, and educators to support young children’s social emotional well-being. 

Marlena Williams

Registered Psychotherapist (Qualifying) & Psychometrist

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Marlena is a Registered Psychotherapist (Qualifying) and Psychometrist. She completed her M.A. in Counselling Psychology at McGill University. Marlena has experience working in clinical, remote, research-based, and private practice settings.


She is currently working with children and adolescents under the supervision of Dr. Petra Gyles. Marlena practices through a primarily cognitive-behavioural, person-centred lens, and has experience helping individuals with
anxiety, self-esteem, depression, trauma, interpersonal issues, and attention deficit hyperactivity disorder (ADHD). Marlena strives to create a warm, collaborative, and engaging space for her clients.

Sarah Bjornson



Sarah is currently a second year Master’s student in the Clinical Developmental Psychology program at York University. She completed a Bachelor of Arts (Honours) in Psychology at the University of Regina in 2018. She has previously worked as an Applied Behaviour Analysis interventionist and an elementary
educational assistant. Her current research focuses on understanding quality of life for children with Autism Spectrum Disorder and Developmental Disabilities as well as their families (particularly in the context of the education system). She will be beginning her PhD in Clinical Developmental Psychology in fall 2024 and plans to continue working with children with neurodiversities.

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Dr. Gyles specializes in therapy for children and teens targeting depression, anxiety, academic anxiety, OCD, perfectionism, trauma, school struggles, and social issues.  She uses evidence-based practices and takes a cognitive-behavioural therapy approach, with aspects of positive psychology, mindfulness, emotion focused, and narrative therapy approaches incorporated into treatment.

Dr. Gyles provides psychological, psychoeducational, and neurodevelopmental assessments for preschool and school-age children and adolescents with Autism Spectrum Disorders, Developmental Disabilities, Learning Disabilities, ADHD, behavioural issues, social-emotional issues, and diagnostic assessments for mental illness.  She completed specialized training at the University of Michigan for Autism Spectrum assessment (e.g., ADOS-2, ADI-R).

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