She wrote the business case for and set up a psychotherapeutic day and outpatient programme for hospitalised patients with severe and complex personality disorder. Within that service she developed the Relational Affective Model, an adapted therapeutic community model for patients with transdiagnostic presentations including eating disorders, functional disorders substance misuse and autistic spectrum disorder. In 2014 she was elected Chair of the Medical Psychotherapy Faculty Executive at the Royal College of Psychiatrists and became a Fellow of the College. 

In 2015 she convened a group of organisations, the Talking Therapies Task Force (TTTF) to make the case for investment in psychotherapeutic pathways for people hospitalised with a diagnosis of Personality Disorder. The TTTF supported the HEARD study (Health Economics and Relational Disorder) and funded the Health Economic Analysis and publication in a report by the Centre for Mental Health (TTTF-CfMH report – Improving support for people with complex mental health difficulties.pdf). The report was launched in the UK Parliament in April 2025. 

She continues to campaign for the implementation of the findings of the report in the NHS and social care in the UK. She investigated the neuro-psychoanalytic basis for the Relational Affective Model in a functional neuroimaging study in her PhD completed in 2024. She is collaborating with researchers to undertake further post-doctoral analyses and continues to write about the Relational Affective Model and her findings. 

She is now developing training in the model for use in mental health services and supported housing, currently working for the housing charity Community Housing and Therapy. She also works in private psychotherapeutic practice in Exeter.

Prizes

Dr Mizen was awarded the Michael Fordham prize 2023 for her paper ‘The Self and Alien Self in Psyche and Soma’.

She was awarded a prize for Innovative Excellence by the British Psychoanalytic Council in 2025.