While it isn't for everyone by any stretch, depression, can more a more 'enjoyable' state than drug induced happiness. Some of us, when depressed, attain a keen (if painful) awareness of evil. Awareness is a good thing. Some of us, when depressed, are intensely creative. Creativity is a good thing. Very near all my poems were written while on the low end of a mood swing. Also, if you have bipolar disorder, then the depression alternates with a fun, manic euphoria, which 'leveling' (a psychiatrist's term, not mine) anti-depressants can smother. And some people appreciate strong emotion for its own sake. Whatever the emotion is, it's real. It let's you know you are alive and feeling. Did you ever pick a scab and savor the sting? Depression is an opportunity to wallow in oneself, which is a good thing unless you are too scared to venture into your own mind.

icicle: You say Depression...can inhibit the patient's ability to be productive or to engage in life-affirming activities (i.e. poetry). Since when is poetry (such as I speak of, anyway) productive, or life-affirming? Far from it! Poetry by a depressed person is a heaving sigh. And if a depression is not so paralyzing that the person suffering from it cannot hold a pen, it is still possible, and often its content is provided by the thoughts the depression induces. Poetry is NOT productive. It does not create something anyone can really use, it does not (usually) earn a lot of money. It is NOT life affirming, for crying out loud! it's life condeming. I have sat in one spot on the floor for hours, too permeated, in your words, spiritual paralysis, a sense of worthlessness, emptiness, exhaustion to move, and yet I was writing...weakly writing, the lines on the page were light, but I could put my dark thoughts into words.