Shared decision making (SDM) interventions aim to improve client autonomy, information sharing, and collaborative decision making, yet implementation of these interventions has been variably perceived. Using interviews and focus groups with clients and clinicians from mental health clinics, we explored experiences with and perceptions about decision support strategies aimed to promote SDM around psychotropic medication treatment. Using thematic analysis, we identified themes regarding beliefs about participant involvement, information management, and participants' broader understanding of their epistemic expertise. Clients and clinicians highly valued client-centered priorities such as autonomy and empowerment when making decisions. However, two frequently discussed themes revealed complex beliefs about what that involvement should look like in practice: (a) the role of communication and information exchange and (b) the value and stability of clinician and client epistemic expertise. Complex beliefs regarding these two themes suggested a dynamic and reflexive approach to information management. Situating these findings within the Theory of Motivated Information Management, we discuss implications for conceptualizing SDM in mental health services and adapt Siminoff and Step's Communication Model of Shared Decision Making (CMSDM) to propose a Communication-centered Epistemic Model of Shared Decision Making (CEM-SDM).