Acute behavioural disturbance in the context of substance use: case series analysis of coroner reports

Background Acute behavioural disturbance (ABD) is a contested term describing severe agitation and behavioural dysregulation, often preceding sudden death. Concerns regarding diagnostic clarity, racial bias and law enforcement restraint have been raised, and its clinical and forensic utility have been questioned. Aims To characterise fatal ABD cases following substance use to inform clinical management, forensic interpretation and policy. Method Fifty-one deaths consistent with ABD were identified from the National Programme on Substance Use Mortality (NPSUM) using textual screening and Royal College of Emergency Medicine and Faculty of Forensic & Legal Medicine criteria. Results All cases met Royal College of Emergency Medicine criteria and most met Faculty of Forensic & Legal Medicine (84.3%) criteria. Agitation was the most frequently observed sign (86.3% of cases). Stimulants, particularly cocaine and amphetamines, were also detected in 86.3% of cases, but not necessarily in the same cases, and the rate of stimulant detection was almost three times higher than that in in the broader NPSUM cohort (32.1%). Cocaine concentrations were higher in ABD cases than in all NPSUM cocaine-related deaths (0.848 mg/L v . 0.105 mg/L). Compared with the NPSUM cohort, ABD decedents were significantly younger (30.2 ± 7.5 v . 40.5 ± 13.4) and more likely to be male (92.2 v . 73.4%), from racially minoritised backgrounds (21.7 v . 3.9%) and living in deprived areas (87.0 v . 75.9%). Conclusions Variability in diagnostic criteria highlights a need for clearer ABD definitions. Toxicology testing may assist in refining the ABD construct, but its results must be interpreted within broader clinical and social contexts. These findings support avoiding use of ABD as a stand-alone cause of death but retaining it as a clinical descriptor prompting urgent treatment, monitoring and reduced reliance on prolonged restraint.