[edited] Exhaustion from stressful life events can result is extreme, suicidal depression that definitely qualifies as "mental illness" - not just a few "negative feelings".
There is really no reason to be so hostile. Perhaps to show respect to the issue under discussion (depression) we could all resolve to be a little kinder to those we speak with.
Contrasting normal everyday sadness versus clinical depression, requiring medication, is accurate.
http://www.nimh.nih.gov/health/topics/depression/index.shtml
I don't see anything there that indicates that sadness must be "without cause" to constitute depression.
Contrasting normal everyday sadness versus clinical depression, requiring medication, is accurate.
True. But we should be careful when making that distinction, whether for ourselves or others, as the line isn't necessarily cut and dried. I think just dismissing someone's report of being "depressed" as "that's just normal sadness" is a very dangerous mindset. If someone's sad enough to choose the label "depressed" for themselves, that alone probably suggests that it's a matter to be taken seriously.