Abstract
This article argues that the Mass Observation Project (MOP) at the University of Sussex offers a unique window onto the history of mental health and the voices of those who have lived with mental health conditions during the late-twentieth century. This article analyses how a sample of MOP participants use their writing to reflect on their experiences, and compose narratives about, mental illness over time. More specifically, we suggest that MOP's capacity for the longitudinal study of individual respondents (underutilised by historians of mental health) offers exciting historiographical and methodological possibilities, not just in the history of mental health but for historians of medicine more generally. We conclude by considering how, for a handful of the participants in the project, mental health is entwined with MOP, as project participants deploy the archive to write about their experiences and even find something akin to therapy in the narrative act.