Unstable in example sentence
And at a time when the stereotype about artists is that they are mostly bitter, pretentious, often mentally unstable people who live in decrepit urban settings, Goldsworthy seems to be the opposite: a stable, unpretentious, family oriented person who loves nature and lives in a small village in Scotland (of course, I'm sure those are the same reasons why he's shunned by some people on the art world who found his works fluffy or superficial).