
A LITTLE MORE ABOUT ME
Hi, I’m Marie.
MARIE-PIERRE CASTONGUAY, MSW, RSW, SEP
I’m a Registered Social Worker and psychotherapist with over a decade of experience supporting individuals and couples. I’ve always been curious about people, the relationships we build, the stories we carry, and the parts of ourselves that become visible when our lives intersect with someone else’s.
That curiosity is at the heart of my work. I’m interested in understanding what has shaped you, but I’m equally interested in who you are today, what already exists alongside the difficult parts, and how you want to live from here.
“I believe that there’s nothing quite like a relationship for showing us ourselves.”

What it’s like to work with me
Warmth and honesty can exist in the same room. I lead with compassion while also valuing clarity and directness. I listen to the stories you bring while staying curious about what is happening alongside them: what you notice in your body, what unfolds in your relationships, and the meanings you have made from what you have lived.
I’ll share what I notice, ask questions that invite us to look a little closer, and help us stay with what is happening in the moment. Together, we can understand what has shaped you, explore what might feel different, and make more room for the parts of you that are already there.
A RELATIONAL WAY OF THINKING
We don't become ourselves in isolation.
Who we are has been shaped in relationship with families, partners, friendships, communities and the larger worlds we have lived within. Those experiences can leave wounds, but they also give us belonging, meaning, pleasure, resilience and ways of knowing ourselves.
A LITTLE OF THE PROFESSIONAL STUFF
The work behind the work.
Marie-Pierre Castonguay, MSW, RSW, SEP is a Registered Social Worker with the Ontario College of Social Workers and Social Service Workers (OCSWSSW), with a clinical focus on couples, relationships, attachment and relational experiences.
Education & Training
Areas of Focus
- Master of Social Work (MSW)
- Registered Social Worker (RSW)
- Somatic Experiencing Practitioner (SEP)
- PACT Level 2 Trained, Psychobiological Approach to Couple Therapy
- Training in Narrative Therapy
- Attachment-based and relational psychotherapy
- Certified Clinical Supervisor
- Couples & Relationship Dynamics
- Attachment & Relational Patterns
- Relational & Developmental Trauma
- Grief, Loss & Betrayal
- Life Transitions
- ADHD & Neurodivergence in Relationships
- Nervous System Regulation
Perhaps we’ll have something to explore together.
If you're interested in working together, you're welcome to book a complimentary 15-minute consultation. It’s a chance to meet, talk briefly about what brings you here, and see if we’re a good fit.
I look forward to meeting you.