In my opinion you can not go wrong with a gift of time… What I mean is visit your friend and have a chat or a coffee. If possible take them out. We all get so wrapped up in how busy life gets, so if you share / give some time it has massive value.
if you need to hand something over you might want to try some kind of voucher for something that your friend has an interest in.
I am rubbish at gifts so I will shut up. Gifts are for people irrespective of any underlying condition, just give it a little thought. I.E no footballs for friends with leg issues, no books for friends with reading issues or no origami gifts for friends with hand issues.
i hope you don’t think I am being simplistic.
good luck Mick