Addiction therapists & psychiatrists in Fullerton, CA

I am a Psychiatric Mental Health Nurse Practitioner (PMHNP) who provides compassionate, evidence-based care for adults. My approach is clinical, trauma-informed, and whole-person; I look beyond symptoms alone and consider the many parts of life that shape mental health. I believe care should feel collaborative, supportive, and not overwhelming. My goal is to help you feel understood while creating a treatment plan that fits your life, values, and goals. Whether you are seeking medication management, in-office IV or IM ketamine treatment, or support through a difficult season, I want you to feel safe, respected, and empowered.

I am dedicated to helping teens struggling with trauma and self-harm behavior. My experience working with Orange Unified School District, running groups from grade 6-12 for students struggling with emotional and behavioral problems has given me unique insight into not only helping teens, but also working with the families, schools, and community to provide more effective treatment. I have partnered with Western Youth Services in helping at risk teens and low income families in helping adolescents to overcome academic barriers and families cope with serious defiance and drug use.

I have been a psychologist for 44 years and worn many hats: schools, private practice, clinics and agencies. Experience counts for a lot! I am dedicated to my patients reducing their suffering.

Hi, I'm Tandrea Thysell, a California-based Marriage & Family Therapist. I've been providing therapy for most of my life (I think I was born to do this!), but professionally for more than 10 years.

Welcome and thank you for taking the time to learn more about me. As a licensed therapist practicing in both California and New York, I believe deeply in the inherent resilience and transformative potential within every individual. I earned my Master’s Degree in Mental Health Counseling from Teachers College, Columbia University. Throughout my clinical practice, I have supported clients across all life stages in navigating complex emotional challenges, including trauma, anxiety, and depression, while empowering them to cultivate healthy, fulfilling interpersonal relationships.

Clients often describe me as warm, approachable, and easy to talk to. I aim to create a supportive and engaging space where you feel safe to be emotionally open, while also bringing a sense of ease.

At the core of my style is curiosity. I’m drawn to the “why” - why we feel, think, and respond to life the way we do. I take a holistic and at times existential approach, exploring not just immediate challenges, but the deeper patterns, life transitions, and questions of meaning that shape your experience.

I draw from a wide range of personal and professional experiences, including working directly with and overseeing a large and diverse group of clients. This allows me to adapt different techniques and perspectives to support growth, insight, and lasting change. Throughout the process, I remain thoughtful, engaged, and focused on what will be most helpful for you.