" . . .depression has repeatedly been shown to be associated with greater realism – provided the depression is not too severe. . . The evidence is that this is not because insight makes you depressed, but because, up to a point, being depressed gives you insight. In understanding one’s role in bringing about a certain outcome, depressives are more ‘in touch’ with reality even than normal subjects. . . "

― Iain McGilchrist , The Matter With Things: Our Brains, Our Delusions, and the Unmaking of the World