This article explores the psychological impact of growing up with a parent with a mental illness. A life course Model of Acquiescence is developed to show how coping strategies developed by children go on to have impact into adulthood. Undertaking biographical narrative interviews with 20 adults who had grown up with a parent with a mental illness produced accounts from childhood to the current day. Thematic narrative analysis was used to gain insight into how the participants made sense of their parent’s mental illness and their own role within it. Participants recalled experiences and family circumstances that were traumatic, unsafe and overwhelming. They dealt with these by attributing adversities to the mental illness and focusing solely on the vulnerabilities of their parents, thus adopting a caring role and ignoring their own needs. Most presented themselves as resilient, adaptable and resourceful, in employment and with intact relationships. However, despite this apparent success, all expressed a profound sense of lost opportunity and low self-esteem. In the Model of Acquiescence, we illustrate how and why children adapt to challenging and complex family experiences and explain how the personal and interpersonal process of parentification develops. An individual positions themselves as insignificant, powerless and silenced, only able to affect change or maintain relationships by anticipating, identifying and meeting other people’s needs. This model underlines the need to support such children’s psychological wellbeing using a whole family approach to understand the impact of parental mental illness and centre the child’s needs.