In the ACT a power of attorney doesn't cover treatment for mental illness. A separate direction is required. The Mental Health Act 2015's sections on advance care directives implies that one doesn't complete such a directive until one has a mental health condition. So does the ACT Mental Health Consumer Network's 'My Rights, My Decisions Form Kit - by addressing it to 'mental health consumers'. For all other health care matters the recommendation is to complete a directive before the time when the directions might be required. My question is: is it (a) permissible, and (b) sensible to complete a directive under the Mental Health Act 2015 before one has been diagnosed with a mental illness?