AbstractBackgroundDespite increasing calls for shared decision making (SDM), the precise mechanisms for its attainment are unclear. Sharing decisions in mental health care may be especially complex. Fluctuations in service user capacity and significant power differences are particular barriers.Objective and designWe trialled a form of facilitated SDM that aimed to generate patients' treatment preferences in advance of a possible relapse. The ‘Joint Crisis Plan’ (JCP) intervention was trialled in four mental health trusts in England between 2008 and 2011. This qualitative study used grounded theory methods to analyse focus group and interview data to understand how stakeholders perceived the intervention and the barriers to SDM in the form of a JCP.ResultsFifty service users with psychotic disorders and 45 clinicians participated in focus groups or interviews between February 2010 and November 2011. Results suggested four barriers to clinician engagement in the JCP: (i) ambivalence about care planning; (ii) perceptions that they were ‘already doing SDM’; (iii) concerns regarding the clinical ‘appropriateness of service users’ choices'; and (iv) limited ‘availability of service users’ choices'. Service users reported barriers to SDM in routine practice, most of which were addressed by the JCP process. Barriers identified by clinicians led to their lack of constructive engagement in the process, undermining the service users' experience.ConclusionsFuture work requires interventions targeted at the engagement of clinicians addressing their concerns about SDM. Particular strategies include organizational investment in implementation of service users' choices and directly training clinicians in SDM communication processes.