A good friend and therapist once described depression as having two manifestations: "Big D" and "little d."  Little d is what we all experience on occasion.  Being down-in-the-dumps; feeling blue; discouraged; disheartened.  When others talk to little d they say things like, "Cheer up," or "Pull yourself together."  They encourage you to get out of yourself and do something for someone else.  They take you out to do something fun.  Often it works, but when it doesn't, little d eventually runs its course in a few days, the sun comes up, and life looks a little brighter.  Big D is to little d like double pnuemonia is to the sniffles.  It is clinical depression.  It is as if the dementors of Harry Potter fame have sucked everything good thing out of you and you cover your mouth so they can't suck out your very soul.  Big D has lots of symptoms.  The most common in an overwhelming sense of drowning in sorrow.  Big D's victims feel helpless and hopeless.  They cast their minds around looking for the tiniest glimpse of light and find none.  Life itself becomes a burden.  No one can completely understand how unspeakably awful Big D is unless they've experienced it.  There is nothing I can recall to compare.  Today, I'm feeling little d.  I'm sad, but I know it will pass and I can do some proactive things, like serving others, to expedite its passing.  But I have also experienced Big D.  It is a condition I hope to never experience again in this lifetime.  For those of you who haven't had Big D, here is a word of caution:  Do not talk to Big D the same way you would talk to little d.  It will only make things worse.  Big D is a medical condition.  It requires professional intervention in most cases.  If you encounter Big D in a friend: listen; reflect; love.  Don't minimize.  Don't discount.  Don't give platitudinous advice.  Do encourage seeking help.  I am strong and wise when I seek help.  I am kind when I encourage others in need to do so.