How Lilly Gilded Prozac's Profile

This spring, Jeff Weise shot himself dead after taking the popular antidepressant Prozac.

He scored national headlines because he took nine innocent people down with him in the worst school shooting rampage since Columbine. Some now wonder whether Weise's antidepressant -- rather than depression itself -- may have finally pushed the troubled teenager over the edge. After all, unstable Prozac users have been pulling the trigger for years.

Joseph Wesbecker killed himself and eight others while taking Prozac back in the late 1980s, when the still-new drug was viewed as a miracle cure for depression. Relatives of the survivors blamed Prozac and sued its maker, Eli Lilly (LLY Quote), for damages. That case, which ended in a settlement, began to expose serious problems with drug research that have grown even more obvious over time.

By now, internal documents have surfaced highlighting concerns about drugs like Prozac -- known as selective serotonin reuptake inhibitors, or SSRIs -- that date back to their early clinical trials. Worried health care experts have long attempted to make this evidence known, but they have found themselves drowned out, and even attacked, by powerful scientists with close ties to the drug industry.

In this second installment of a five-part series examining conflicts in the drug industry, TheStreet.com examines how big pharmaceutical companies -- heavy on marketing know-how but increasingly strapped for big-selling new drugs -- pressed the popular antidepressants into service in spite of lingering questions over their safety.

The drug companies continue to stand behind their blockbuster antidepressants and market them to the masses. And they keep raking in billions of dollars in profits -- more than any other industry -- as a result of their success.

But prestigious medical journals, including those that regularly publish research by the well-connected scientists, have called for ethical reforms. So have consumer watchdog groups. Industry critics insist that drugmakers exert too much influence over researchers, consumer groups and even the government agency charged with regulating them.

As a result, the big pharmaceutical houses' reputations -- and their share prices -- have begun to take a hit. Shares of Eli Lilly, which now has two major antidepressants on the market, have lost a quarter of their value over the past year. Shares of Pfizer (PFE Quote), which makes bestseller Zoloft, have fallen by a similar amount.