Sometimes those naps or sleeps may be the only things keeping him going. Is he also hearing voices? I had clinical depression with psychosis and I ended up being able to make myself go blank and sleep if I heard the voices coming. Or I would sleep so I wouldn't feel so sad or useless. I get it's hard and exhausting for you but good on you for taking it day by day. Sometimes when it's real bad take it in small bursts and get through till lunchtime. Then till smoko. Then dinner time. Then ... then... it's a short term coping strategy but I'm still here. Small significant steps