The Mental Capacity Act (MCA) protects individuals’ rights to make decisions. However, for those with Prader-Willi Syndrome (PWS), especially regarding food and finances, the MCA can present challenges.
PWS involves a biological drive to eat excessively and difficulties with impulse control and risk awareness. Although individuals may understand risks intellectually, neurological factors often impair their ability to regulate behaviours that threaten their health and safety. Similarly, someone may appear to have the capacity to manage finances, but PWS involves compulsive or risky spending, especially around food.
Because the MCA focuses on cognitive understanding, it may not fully address these behavioural complexities. Professionals must therefore balance respecting autonomy with safeguarding wellbeing.
There have been multiple cases of people with PWS dying from overeating shortly after they were deemed to have mental capacity around food and money.
As well as dying from obesity-related complications, people with PWS can and do die from gastric rupture following a single binge eating episode, even if they are not obese.
PWS affects decision-making, particularly regarding eating behaviour and diet.
While individuals with PWS can make decisions, their capacity may fluctuate, necessitating supervision and environmental controls.
The following recommendations are taken from "The Mental Capacity Act: Supporting People with PWS"
Research highlights the risks associated with uncontrolled access to food for individuals with PWS, emphasizing the need for a food-managed environment to prevent significant weight gain and associated health issues.
Interventions in a person's autonomy must be justified by law, necessary, and proportionate. This aligns with Article 8 of the Human Rights Act, ensuring respect for private life while addressing the risks posed by unmanaged overeating in PWS.
For children, parents or guardians have a duty under the Children Act (1989) to act in their best interests, including managing the eating environment. If a child is 'Gillick competent,' they may consent to aspects of their care and treatment.
Adults with PWS need a food-managed environment. Support can be provided through:
1. Consent to Restrictions: Adults who understand the risks and voluntarily agree to supervision or environmental controls.
2. Mental Capacity Assessments: If an adult cannot consent due to a 'disability of the brain or mind,' the MCA allows others to make decisions in their best interests, ensuring any restrictions are necessary and proportionate.
3. Other Legislation: The Mental Health Act is less relevant unless severe mental health issues are involved.
Capacity must be assessed for specific decisions at specific times. Individuals with PWS may need detailed capacity assessments, especially if their decision-making ability is inconsistent or if they refuse support.
Information on PWS, the risks of unmanaged eating, and available support should be provided to help individuals make informed decisions. Capacity assessments must distinguish between understanding information in theory (decisional capacity) and applying it in practice (executive capacity).
In PWS, restrictions to limit unsupervised eating are usually required. Such interventions must comply with Section 6 of the MCA, ensuring they are justified and necessary to prevent harm.
The Restraint Reduction Network (RRN) highlights that restraint should always be a last resort, used as little as possible and for the shortest time.
For those with PWS, however, restrictions around food are considered to be the least restrictive option and need to remain in place.
PWS-Specific Challenges
What good professional practice looks like:
People with PWS typically present with low muscle tone, which can impact cardiovascular and respiratory function. As a result, the use of physical restraint carries a significantly increased risk of harm and has, in the past, led to serious, life-altering injuries.
It is therefore essential that all professionals are fully aware of these risks and understand the need for alternative strategies.
The documents below are designed to support those carrying out mental capacity assessments of someone with PWS.
This checklist for mental capacity assessors explains and gives examples of how PWS can impact memory, emotions, and understanding in real world situations
This guide to assessing mental capacity in PWS explains how and when capacity can be impacted by PWS
Sarah Brindle: PWSA Mental Capacity Lead
Sarah is our resident expert in mental capacity, and can provide advice and support to professionals and families caring for those with PWS.
Sarah can support you by:
Postal correspondence address:
Prader-Willi Syndrome Association UK
C/O Metcalf’s Commercial Decorators
3 Deer Park Road
Moulton Park
Northampton
NN3 6RX
Phone: +44 (0)1332 365676
Email: admin@pwsa.co.uk
Registered Charity number
England and Wales: 1155846 Scotland: SC053700