Mental Capacity, Consent and Best Interests in PBS Practice
Positive Behaviour Support sits directly within the legal framework of the Mental Capacity Act. Within Human Rights, Legal Context & Ethical Decision-Making and the PBS principles and values, providers must evidence that decisions about risk, restriction and support are grounded in lawful capacity assessment and valid consent.
This article focuses on how mental capacity is assessed and revisited in PBS, how best-interest decisions are made when capacity is lacking or fluctuates, and how providers demonstrate that decisions remain person-centred rather than organisationally convenient.
Why mental capacity is central to PBS
PBS plans often affect fundamental rights: freedom of movement, association, privacy, and autonomy. Capacity is decision-specific and time-specific, yet services sometimes default to blanket assumptions (“they lack capacity generally”) or fail to revisit assessments as skills develop or circumstances change.
Operationally, poor capacity practice creates two risks: unlawful restriction and erosion of trust with people, families and commissioners. Strong capacity practice, by contrast, strengthens PBS credibility and safeguards providers.
Operational example 1: capacity assumed rather than assessed
Context: A person with learning disability and autism was supported under a long-standing PBS plan that limited community access at certain times. Capacity to consent had not been formally assessed for several years.
Support approach: The provider introduced a decision-specific capacity assessment focused on consent to community access arrangements and risk management strategies.
Day-to-day delivery detail: Staff used accessible communication tools (visual scenarios, simple choice mapping) over several sessions. Capacity was assessed in calm periods, not during distress. The assessment explored understanding of risk, alternatives, and consequences rather than abstract concepts.
How effectiveness is evidenced: The person demonstrated capacity to consent to a revised plan with fewer restrictions. Documentation showed a clear audit trail: assessment method, conclusion, and how the PBS plan changed as a result.
Fluctuating capacity and PBS delivery
In PBS, capacity often fluctuates due to anxiety, trauma responses, mental health relapse or environmental stress. This does not remove the obligation to seek consent wherever possible.
Operationally, services should plan for fluctuation by:
- Identifying when capacity is most likely to be present.
- Separating crisis management from long-term decision-making.
- Embedding advance preferences into PBS plans.
Commissioner expectation: clear MCA application
Commissioner expectation: Commissioners expect providers to demonstrate that capacity assessments are decision-specific, proportionate and revisited. They look for evidence that best-interest decisions are not used to shortcut consent or avoid complexity.
Regulator expectation: lawful authority and involvement
Regulator / Inspector expectation (CQC): Inspectors examine whether people are supported to make decisions wherever possible, whether capacity assessments are robust, and whether best-interest decisions involve appropriate parties. In PBS contexts, they also look for links between capacity decisions and restrictive practice governance.
Operational example 2: best-interest decision without drift into restriction
Context: A person temporarily lost capacity during a period of acute mental health deterioration, with increased risk of self-harm during community access.
Support approach: A time-limited best-interest decision was made to adjust support arrangements, with explicit criteria for review and step-down.
Day-to-day delivery detail: Staff implemented enhanced observation only during defined high-risk periods, while preserving choice and autonomy elsewhere. Daily wellbeing indicators were recorded to inform reassessment.
How effectiveness is evidenced: Capacity was formally reassessed once the crisis subsided. The best-interest record showed proportionality, involvement of family and clinical input, and clear evidence that restriction reduced as capacity returned.
Best-interest decision-making that withstands scrutiny
Defensible best-interest decisions usually include:
- A clear statement of the decision being made.
- Evidence that capacity was assessed and why it was lacking.
- The person’s past and present wishes.
- Views of family, advocates and relevant professionals.
- Why the chosen option is the least restrictive.
Operational example 3: avoiding “best interests by habit”
Context: A service routinely applied best-interest decisions for financial management without reviewing capacity.
Support approach: The provider introduced annual decision-specific capacity reviews linked to PBS progress.
Day-to-day delivery detail: Staff supported skill-building around budgeting and choice, using structured opportunities to demonstrate understanding.
How effectiveness is evidenced: Several people regained capacity for specific financial decisions, reducing restrictive oversight and strengthening autonomy outcomes.
What good documentation looks like
Strong PBS documentation links capacity, consent and restriction clearly. It avoids generic statements and shows how decisions evolve over time.
Where providers do this consistently, PBS remains lawful, ethical and genuinely person-centred.