Jenn Deffendall, Ph.D., C.Psych.

My name is Jenn Deffendall. I am a registered Clinical and Rehabilitation Psychologist in Ontario and I provide psychological assessment and treatment for adults.

I have earned degrees in Clinical Psychology (M.Sc. and Ph.D.) from the University of Central Florida as well as a degree in Clinical Psychopharmacology (M.Sc.) from Fairleigh Dickinson University. My professional background is diverse: I have trained and worked in private practice, inpatient and outpatient hospital clinics, residential treatment, community counseling and university settings. I completed residency at the University of Chicago Medical Centre.

My clinical experience is extensive and includes working with a range of problems including depression, anxiety and phobias, posttraumatic stress, adjustment to complex medical conditions including chronic pain and cancer, insomnia, and addictions (alcohol, tobacco, cannabis and other substances, gambling, internet, sex and pornography).  I also work with those who may be experiencing short- or long-term disability due to illness or injury. I work primarily within a Cognitive Behaviour Therapy framework, with the ability to integrate elements of specialized treatments (such as Dialectical Behaviour Therapy, Motivational Interviewing and mindfulness- and acceptance-based strategies) as needed to ensure treatment is effective. 

My approach to treatment is warm, caring and collaborative. I build a strong therapeutic relationship with my clients, working together to understand and improve emotional, cognitive and physical problems as they impact daily life. Therapy is both supportive and skills-based, with the goal of fostering a sense of mastery and resilience in life.

I provide psychological services to address:

• Depression
• Anxiety and phobias
• Trauma/PTSD
• Life and relational stress
• Transitional stress (school, work, divorce, retirement)
• Insomnia
• Psychological symptoms related to complex medical conditions including chronic pain and cancer
• Addiction (alcohol, tobacco, cannabis and other substances, gambling, internet, sex and pornography)
• Short- and long-term disability (including LTD, MVA and WSIB-funded services)

Maria Costaki (She/Her), MEd, MACP, RP (Qualifying)

Hello! My name is Maria Costaki and I am a Registered Psychotherapist (Qualifying). I was also an elementary school teacher in Ontario for 33 years. My passion for helping others lead me to pursue a Master of Arts in Counselling Psychology (MACP) so that I can work as a psychotherapist with adults, adolescents, and children.

Our world is becoming increasingly stressful and life has many challenges; I hope that in our work together I can support you to develop the coping skills needed to navigate these challenges so that you can live a more fulfilling life.

I offer supportive, client-centred, strengths-based, inclusive care to all my clients in a safe, non-judgmental environment. I bring a culturally sensitive approach to therapy and offer services in English, French, and Greek. I look forward to working with you in person and/or virtually.

I provide psychotherapeutic services to address:

• Depression
• Anxiety, phobias, OCD
• ADHD and Executive Functioning Skills
• Work-life balance
• Parenting challenges
• School related challenges for children, teens, and young adults
• Stress and perfectionism
• Teacher support

Ellie, Greeter
Between naps in the office, Ellie brings all of her 12 pounds of charm to saying hello and accepting treats. She received her undergraduate education at Scholars in Collars Dog Training, where she completed Levels 1-3 of Obedience Training. She then went on to pursue advanced studies in Trick Training.