23 Treatment refusal can occur in the presence or absence of decision-making capacity.
24 The core elements of capacity are the ability to understand the information relevant to the decision, the ability to use or weigh that information as part of the decision-making process, and to communicate the decision.
25 Common law establishes that an adult is presumed to have the capacity to consent to or refuse medical treatment unless that presumption is rebutted.
26 However, capacity may be affected by symptoms of mental and physical illness, emotional state and cognition, which may fluctuate over time and resolve with treatment and support.
27,28 With psychosis, for example, there may be symptoms such as delusional beliefs leading to mistrust of clinicians or denial of illness.