The ability to make decisions (and thereby its assessment) can be complex. It may be affected by a combination of factors that vary between individuals. Even when cognitive functioning may be compromised (for instance, by dementia), a person may still be able to express important deep-rooted values underpinning their decisions. The circumstances may demand that these different elements are explored in greater or lesser detail in making conclusions about an individual’s decision-making capacity. This may add to the complexity of an assessment. From the outset, to make an adequately informed treatment or other decision, you must have sufficient information, be able to make the decision free from coercion and have mental capacity.

Notwithstanding the challenges, with appropriate thought, preparation and attention to documentation, it should be possible to record a legally defensible assessment of capacity for most situations that arise in clinical practice. The purpose of this chapter is to provide an accessible approach to capacity assessment and its recording.