We talk about mental health and mental illness quite often these days. Is it taking the metaphor too far to say we should practise good mental nutrition and get plenty of mental exercise? Well, whether or not it stretches the metaphor, I think the mental equivalent of eating junk food and sitting still all day is bound to catch up with you, one way or another.
Mokalus of Borg
PS - Probably not with a serious mental illness, though.
PPS - Just mental laziness.