Challenges in decision-making capacity in the acute hospital setting: two years on from the implementation of the Assisted Decision-Making (Capacity) Act 2015

Two years on from the implementation of the Assisted Decision-Making (Capacity) Act (ADMCA) 2015, significant legal uncertainty persists in Ireland's acute hospitals for the care of people who lack capacity to consent to treatment. Consultation-liaison psychiatrists must navigate a legal landscape where clear lacunae have emerged in the regulation of frequently encountered clinical scenarios. We identify three of these - eating disorders requiring refeeding, refusal of life-saving treatment, and unsafe discharges - where neither the ADMCA nor the Mental Health Act 2001 provide legal authority to intervene. In such cases, the Inherent Jurisdiction of the High Court has become the default mechanism for authorising treatment or deprivation of liberty, raising serious concerns about proportionality, clinical delays and uncertainty, cost, and consistency. We also consider a fourth category of patients who require immediate life-saving treatment, and the legal status of Advance Healthcare Directives in this context. Many of the patients who fall into these categories will have an established or suspected mental illness requiring the clinical input of a consultation-liaison psychiatry team.We contrast Ireland's evolving capacity legislation with developments in England and Wales. Reflecting on these comparisons, we consider the proposed Protection of Liberty Safeguards may provide some clarification but also contain potential risks of becoming unwieldy and bureaucratic and still fail to provide a workable statutory basis for authorising medical <i>treatment</i> in acute hospital settings. A proportionate, patient-centred, and clinically usable legal framework remains urgently needed.