Shared decision making (SDM) is a model of interaction between doctors and patients in which both actors contribute to the medical decision-making process. There is an international consensus across medicine about the importance of SDM interventions, which have raised great interest in mental healthcare over the last decade. Yet SDM is not widely adopted, particularly in the field of psychiatry. The purpose of the present article is to examine, from a patient and physician perspective, the importance of SDM in the management of healthcare with a focus on mental health; it reviews the enablers and barriers (and how to overcome them) to implementing a SDM process in psychiatric practice. SDM models have been developed recently for involving patients with depression in the decision-making process, which could result in augmenting the proportion of patients who adhere to their antidepressant or other treatments for a duration that complies with the current recommendations. To implement this approach, more physicians need training in the SDM approach and access to appropriate tools that help engage in collaborative deliberation, and practice generally needs to be reorganized around the principles of patient engagement.