Assume capacity unless shown otherwise. Capacity is specific to the decision and the time.
Scotland: Adults with Incapacity (Scotland) Act 2000 — a section 47 certificate authorises treatment. England and Wales: Mental Capacity Act 2005 — act in the person's best interests.
Act now
- 1
Emergency treatment to prevent serious harm can go ahead if they lack capacity — document why.
Assess
- Is there an impairment of mind or brain (in Scotland, a mental disorder or inability to communicate)?
- Can they understand the information, retain it, use or weigh it, and communicate a decision?
- Give them every chance: right time, glasses and hearing aids, interpreter, simple language. Treat delirium first if the decision can wait.
Investigations
- 4AT and a delirium screen for reversible causes.
Manage
- Check for a welfare attorney or guardian (Scotland), a health and welfare LPA or deputy (England and Wales), and any valid advance decision.
- England and Wales: best-interests checklist, consult family and carers, IMCA if there is no one, least restrictive option.
- Scotland: AWI principles — benefit, least restrictive, the person's past and present wishes, consult relevant others, encourage residual capacity.
- Document the decision, the assessment and the reasoning.
Escalate when
- Serious or contested decisions, restraint, or a patient trying to leave: senior, psychiatry liaison, legal advice.
Written to current guidance (NICE CG103) · sources checked 14 Nov 2026. We watch NICE for updates weekly.
Sources (3)
- Mental Capacity Act 2005 (England and Wales) and Code of Practicechecked 14 Nov 2026
- Adults with Incapacity (Scotland) Act 2000checked 14 Nov 2026
- NICE CG103 — Delirium: prevention, diagnosis and managementVersion 18 Jan 2023, checked 14 Nov 2026
Reviewed by Aboodee Alhasso, MPharm MRCPharm IP on 14 Nov 2026
Calculators for this
For healthcare professionals, as an aid to clinical judgement — not a substitute for it. Follow your local policy and ask a senior when in doubt.