Naomi
It could be sufficient but I would not rely on it,
The someone needs to engage with the process, if they don't then their DLA will be stopped, so the first thing that they need to deal with is the form.
If they are too ill to complete it then they need to write a short letter explaining this, if they can get a letter from their GP confirming that then it will help, they then need to return the form with the letter to the DWP by the required date.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
