Exercise even if it's just walking, fresh air, healthy food, lots of sleep, talking, writing in a journal, a pleasant environment, peace and quiet, laughter, nature.

Pain increases depression and stress so pain management is important.

Depression is linked to a decrease in seratonin which is why exposure to day light and good sleep patterns can help. You can get melatonin to help with sleep but I'd talk to a doctor first.

Can he do yoga? Kinesiology or other bidy work may help.

Basic things like a clean house and clean sheets can make a huge difference. The more depressed you are the less likely you are to clean so it becomes a vicious cycle.

Lots of nourishing food.