It sounds like you might be talking about two different things: lack of education and mental disorder. You feel like you are unable to work? What do you base that on: lack of skills or a possible disorder? If you have a disorder of some kind and feel that keeps you from working or functioning you will need a Dr. of some kind to validate that in writing so that you can apply for SSDI. If the history of a disorder has been documented (hospitalizations, other treatment, etc.) and you are having trouble functioning then you could have a good basis for receiving disability. If you feel that you can hold a FT unskilled job like a janitor or bagging groceries, etc. then that's not considered a disability.