For this Act, a person has capacity to make a decision in relation to the person's treatment, care or support for a mental disorder or mental illness ( decision-making capacity ) if the person can, with assistance if needed—
(a) understand when a decision about treatment, care or support for the person needs to be made; and
(b) understand the facts that relate to the decision; and
(c) understand the main choices available to the person in relation to the decision; and
(d) weigh up the consequences of the main choices; and
(e) understand how the consequences affect the person; and
(f) on the basis of paragraphs (a) to (e), make the decision; and
(g) communicate the decision in whatever way the person can.