It's based on actual studies and some drugs are worse than others, etc. It's thought to be caused because children/adolescents are "different" chemically/biologically since they're still growing, etc. and what's depression and what isn't isn't as clearcut yet. But it wouldn't just be adolescents if it was a brushoff thing as adults would have that equally?

http://www.medpagetoday.com/Psychiat...ession/tb/3880