It also doesn't mean that these mood improvements are actually useful for treating depression. (For example some studies have shown an increased suicide risk - there is no firm consensus on the topic though: http://en.wikipedia.org/wiki/Antidepressants_and_suicide_ris...)
Drug dependency on SSRI's is a very real thing - I honestly don't see how its any better than an opiate addiction.
Also Big-Pharma funding has a strong and very much negative influence on the objectivity of our scientific body of knowledge. Very often studies/research that have been funded but do not support their conclusions will simply be shelved without publication.