Clinical and severe depression is a mental disease. Those with severe depression have a skewed perception on reality. Oftentimes they develop victim complexes, catastrophic thinking patterns and even conspiratorial beliefs. They cannot function as a worker in a capitalist economy a member of society. Self-medication and suicide attempts are common.

Nowadays there's a blooming movement surrounding depressive realism, which may be equivalent to what you mean by "discouragement". A depressive realist is hypothesized to have a better grasp of reality than the normal, and suffer moderate depression because of it. Of course, most depressive realists would never give up their perceptual capacities, probably out of some form of pride or ressentiment. Being depressed is never fun but occasionally it allows you to feel superior to all the "sheeple". But in general depressive realism is a form of neuroticism.

A depressive realist is hypothesized to have a better grasp of reality than the normal, and suffer moderate depression because of it. — darthbarracuda

I fail to see how qualitative value statements like 'better' or 'worse' contribute to understanding the POV of a depressed individual. I would say that it is a different frame of reference, not necessarily a 'better' or 'worse' one.

Of course, most depressive realists would never give up their perceptual capacities, probably out of some form of pride or ressentiment. Being depressed is never fun but occasionally it allows you to feel superior to all the "sheeple". But in general depressive realism is a form of neuroticism.

I don't think it is a form of neuroticism. It's just a deep mood about the world. The mood itself isn't a manifestation of a neurotic mind. If an unknown to himself Buddhist walked into a clinic and told the doctor that life is suffering and the source of suffering is desire, then should he or she be labeled as 'depressed' or rather in some sense 'enlightened'?