EXCITATION study: Unexplained in-custody deaths: Evaluating biomarkers of stress and agitation.

•Excited delirium syndrome (ExDS) is associated with mortality.•There are no pre-mortem tests or markers to assist in defining the diagnosis of ExDS.•Levels of cortisone are more markedly elevated in ExDS compared with other agitation.•Levels of cortisone are more elevated in ExDS than in strenuous exercise and stress.•Levels of orexin trended to being more elevated in ExDS compared to controls.