Mum heard on the BBC World Service that knitting can reduce depression in older women:
Apparently physical therapists and doctors have noticed that old ladies (and perhaps men – not mentioned) who are in pain and depressed, improved a lot when they took up knitting. They used less medication, were more cheerful and their memories improved.
Doctors think it may be the movements in knitting that help to calm patients. They also suggest that knitting groups overcome feelings of isolation and making nice things makes the ladies feel less useless.
They are starting a proper research programme in Bath to sort out the different factors.
I did a quick search and all I could find was this on BBC Health, which is more about dementia than depression:
Those who had during middle age been busy reading, playing games or engaging in craft hobbies like patchworking or knitting were found to have a 40% reduced risk of memory impairment.
So pick up those needles and stop your mind from deteriorating.