Synopsis
Assess and document decision-making capacity in severe eating disorders, support autonomous choice, identify when a lawful compulsory framework may be required, and apply the correct nation-specific safeguards to life-preserving treatment.
- Presume an adult has capacity; diagnosis, low weight, unusual values, disagreement or a decision clinicians consider unwise cannot by themselves rebut that presumption.
- Capacity is assessed for one clearly defined decision at the time it must be made, after practical support and treatment of reversible barriers to deciding.
- The Mental Capacity Act test in England and Wales, and for commenced Mental Capacity Act provisions in Northern Ireland, includes understanding, retaining, using or weighing relevant information and communicating a choice; Scotland's statutory wording differs, and Northern Ireland retains a dual system while commencement is incomplete. Apply the local test rather than exporting one nation's form, while examining carefully how eating-disorder beliefs affect the person's use of information.
- Record the proposed intervention, material benefits and burdens, alternatives including no treatment, likely consequences, support offered, the person's own reasoning and how any impairment causes the functional inability.
- A capacitous adult's treatment refusal remains valid unless a separate lawful authority applies; a mental-health statute may authorise treatment in defined circumstances even when mental capacity is present.
- When capacity is absent, any substitute decision must follow the applicable jurisdiction's benefit or best-interests process, consultation and least-restrictive safeguards; incapacity alone does not authorise detention or force.
- Law differs across the UK: England and Wales, Scotland and Northern Ireland use distinct capacity and mental-health statutes, terminology, procedures and advocacy roles.
- Mental Health Act 2025 changes in England and Wales are being commenced in phases; clinicians must check which provisions are in force rather than assume the whole Act operates.
- After the June 2026 UK Supreme Court judgment, lack of domestic-law capacity for care or residence does not automatically answer the separate Article 5 question of valid consent to confinement. Establish the person's actual understanding and wishes under current national guidance; mere compliance is not consent, and the judgment does not authorise unwanted treatment or force.
- Feeding without consent is an exceptional treatment requiring an eating-disorder, medical, nursing and legal plan, staff trained for frail patients, and review before every restrictive episode.
Key red flags
Refusal of food, fluid, blood tests, ECG, admission or tube feeding in the context of syncope, awake bradycardia below 40, hypoglycaemia, dangerous electrolytes or organ dysfunction needs urgent joint assessment.
A patient may accurately repeat that death is possible yet be unable to use and weigh that consequence because disorder-driven terror of weight restoration dominates the decision.
Fluctuating attention, hypoglycaemia, infection, intoxication, delirium or severe dehydration can additionally impair capacity and may be partially reversible with immediate treatment and support.
Threats, restraint or covert medication without a clearly identified legal authority, trained staff, proportionality and contemporaneous review create serious clinical, ethical and legal risk.
A young person's refusal of invasive life-preserving treatment requires senior paediatric, psychiatric and legal analysis; parental agreement should not be treated as an automatic answer to every competent refusal.
Investigation priorities
Examine the decision-making functions required by the applicable jurisdiction for the exact proposed intervention.
Management branches
A person appears to refuse or hesitate about a treatment necessary to reduce serious eating-disorder harm.
- Specify the immediate decision, urgency, material risks, reasonable alternatives and consequences of no intervention in accessible language.
- Correct reversible barriers, offer communication support, advocacy and time where safe, then apply the decision-making functions required by the relevant jurisdiction.
- Record the person's own account, statutory and functional evidence, any required causal link, conclusion, review time and how disagreement was separated from incapacity.