Communication in adult psychiatric centers, within the centers teams as well as between these teams and their environment, is an essential tool for quality of care, coherence of healthcare pathways, and quality of life at work for the caregivers. Yet and paradoxically this work of communication in the frame of care has been very little studied. The paper, grounded on fieldwork carried out in five French psychiatric centers describes a diversity of communication practices. This communication appears to be more or less well organized, to give space to oral, written and digital communication, and to mix formal and informal communication. The article identifies the factors favoring differences despite the unifying role of public policy. It shows the challenges for mental health work teams to think communication.