Mental Capacity Act — 5 principles
What it means
The MCA 2005 governs decisions for those who may lack capacity. Its five principles: (1) ASSUME capacity unless proven otherwise; (2) support the person to make their own decision (all practicable help) before deeming them unable; (3) an UNWISE decision does not itself prove incapacity; (4) any decision for an incapacitous person must be in their BEST INTERESTS; (5) choose the LEAST RESTRICTIVE option.
Worked example
A man refuses a recommended amputation. He understands the risk of death, retains and weighs it, and communicates his choice — he HAS capacity, even though the team thinks the decision unwise. The unwise-decision principle protects his autonomy.
In the exam
A patient with capacity declines a treatment the team strongly recommends, fully understanding he may die without it; the team wonders whether they can override him.
What settles it
An unwise decision is NOT incapacity (principle 3) — capacity turns on the PROCESS (understand/retain/weigh/communicate), not the wisdom of the outcome.
Classically confused with
Two-stage capacity test
Source: Mental Capacity Act 2005