Abstract Background To offer optimal care, the mental health system needs new routes for collaboration, involving both interprofessional and interorganizational aspects. The transition from intramural to extramural mental health care has given rise to new dynamics between public and mental health care, introducing a challenge for interprofessional and interorganizational collaboration. This study aims to determine values and expectations of collaboration and to understand how collaboration in mental health care organizations takes shape in daily practice. Methods We conducted a qualitative study using semi-structured interviews and a focus group, in the setting of the Program for Mentally Vulnerable Persons (PMV). Data were analysed following thematic analysis. Results We found three aspect that were considered important in collaboration: commonality, relationships, and psychological ownership. However, our findings indicate a discrepancy between what is considered essential in collaboration and how this ...