Beyond Participation: Politics, Incommensurability and the Emergence of Mental Health Service Users' Activism in Chile.

Although the organisation of mental health service users and ex-users in Latin America is a recent and under-researched phenomenon, global calls for their involvement in policy have penetrated national agendas, shaping definitions and expectations about their role in mental health systems. In this context, how such groups react to these expectations and define their own goals, strategies and partnerships can reveal the specificity of the "user movement" in Chile and Latin America. This study draws on Jacques Rancière's theorisation of "police order" and "politics" to understand the emergence of users' collective identity and activism, highlighting the role of practices of disengagement and rejection. It is based on interviews and participant observation with a collective of users, ex-users and professionals in Chile. The findings show how the group's aims and self-understandings evolved through hesitations and reflexive engagements with the legal system, the mental health system, and wider society. The notion of a "politics of incommensurability" is proposed to thread together a reflexive rejection of external expectations and definitions and the development of a sense of being "outside" of the intelligibility of the mental health system and its frameworks of observation and proximity. This incommensurability problematises a technical definition of users' presence and influence and the generalisation of abstract parameters of engagement, calling for approaches that address how these groups constitute themselves meaningfully in specific situations.