General practitioners (GPs) must be competent in conducting mental health crisis assessments. These are complex, high-risk assessments which can have profound impact on patients, their support networks, health and social care workers and the police. Despite this, GPs receive limited training to prepare. Using scoping study methodology, the first two studies explored what is known about how best to develop training for this crisis assessment. This included a review of the literature and consultation with key professionals involved via four interdisciplinary focus groups. This scoping study identified gaps in training across disciplines, with a call for practical, interdisciplinary learning. Professionals want training that supports the development of decision-making skills, teamworking and opportunities to learn from complex cases. In response to these results three subsequent studies were conducted focusing on the development and delivery of an experiential training approach. This included two development phases of research and a feasibility study, all conducted in line with the medical research council's framework for developing and evaluating complex interventions. The initial development phase was used to adapt an interdisciplinary, forum theatre-based training approach. Two half-day interdisciplinary training events were delivered as part of a feasibility study. Participants (n=68) included approved social worker trainees (n=27), GP trainees (n=22) and police officers (n=19) who completed pre- and post-training questionnaires and attended one of eight focus groups. Quantitative and qualitative data confirm this training was feasible and popular. The final development study enabled refinement of this training intervention ahead of future implementation. There was personal and public involvement throughout all studies. This research has identified key factors to inform the development of meaningful training approaches moving forward. It has also identified a viable interdisciplinary training framework for complex clinical assessments. Such improvements in training is a positive step towards a more cohesive response and better patient care.