You know the boss can get into trouble for talking bad about a employee. There is a law out there that says they can only say rehire or not rehire. Have you talked to him about his work ethics? Honestly I think that you need to stress to him in a non-combative way how you feel about this. If he is having a problems with his meds they might need to be adjusted for his depression. I know that this is hard on you, but you need to put your foot in his butt. Your so stressed and he's probably just sitting there as if nothing is wrong. I am so sorry, just encourage him to keep trying.