What is a mental health power of attorney? The Power of Attorney (POA) is one of the most important real estate planning documents.It provides legal power for loved ones Health care decision If you are incapacitated due to sickness, illness or injury, it represents you. However, if you are suffering from a mental illness, paranoia, or other mental illness due to dementia or other mental health conditions, the standard power of attorney may not authorize the correct help. If you wish to appoint one or more trusted individuals to make decisions about your mental health, then you will need a Mental Health Power of Attorney.