Which disorder are you speaking of? There are many types of mental disorder, some more capable of self-sufficiency than others.

Example: Bi-polar Disorder, series of highs and lows, swinging from the happiest to lowest without indication of mood swing changes and irrational behaviors. A very hard disorder to live with especially if the person with the disorder refuses meds.

Example: Alzhiemer's - client in and out of reality and rational behaviors til they are without lucid moments and incapable of self-sufficiency.

Bi-polar Disorder is a mental illness.

Alzheimer's is a progressive and fatal brain disease.

Just sayin.

Its an illness its not their fault.

Actually Alzheimer's is covered under both medical illnesses and psychological illnesses.