In order to continue to claim your disabled adult child on your income tax return, the following five tests must be fulfilled.
First, the child must be your legal child. Second, the child must be permanently and totally disabled at any time during the year, regardless of age. Three, four, and five do not matter if the first two tests are met.
So, I was just kidding. Only two tests need be met. That is not much red tape, IMHO.