General principles

All adult patients should be presumed to have capacity, unless established otherwise. A mental disorder is not sufficient grounds for deciding that a patient lacks capacity. Nor should you make assumptions based on a person’s appearance, behaviour or because you consider their decisions to be irrational.

Be aware that some people will be able to make simple decisions but may have difficulties with more complex ones; other patients’ capacity may fluctuate depending on their condition. Capacity is decision-specific. The Act advises that patients can be assisting in making decisions by giving them time and support and, where it is necessary, an advocate or interpreter.

Identify the trigger for capacity assessment and confirm validity. This may be progressive memory loss, difficulty in communicating, disorientation, lack of mental flexibility, difficult family circumstances, or at the behest of a concerned family member.