Quoted By:
Only a small fraction of the population actually has legit clinical depression and needs a prescription to rectify it. For the most part, doctors will try to prescribe these things to somebody who merely looks like they're having a bad day. I'm pretty sure they get kickbacks from the drug companies to do this. The drug companies know there's no profit in manufacturing something for a tiny segment of people, so they have to find ways of getting more people on them even if they don't need to be.
TL;DR: These things should only be used by people who really need them. Also, they tend to cause aggression in some people.