Actually...
I work at said drug company (Eli Lilly) and the patent for Prozac expired last year. Whoever wrote the article might want to check their facts out

. If memory serves me, generic Prozac hit the market in September/October 2001.
And let me tell you, this particular drug is just a BLIP on the Eli Lilly screen. They have other drugs that they are aggressively marketing - Xigris, Zyprexa, Gemzar, Evista, and Humilin.
They have three additional drugs that are supposed to be launched next year.
But I digress

......
First, PMS is a serious problem and for many years, lots of people denied its existence. I believe that in some cases, it may need to be treated by medication, in other cases, a change in diet, and in some other cases it's just a slight annoyance much like the common cold is.
Second, Lilly didn't classify it as a mental illness, it's those dern DSM people that did. Whenever a new drug is created, the FDA, of course, requires that it be tied to the diagnosis of some "known" disease. If that's the only place where it's documented, they really have no other choice but to do what they did.
Third, I TOTALLY agree with you on generics. We just had to switch insurance companies and they pretty much force us to take generic unless we want to pay full price for name brand drug. I took generic and it was like taking a sugar pill for me. I am back on the name brand - it's pricey, but worth it.