Approvals, upgrades, a look at antidepressants, and a congressional probe peppered biotech and pharma news, shoving stocks around on Thursday. The result: an even weighting on surprisingly bland health indices.

ZymoGenetics got its go-ahead, an analyst gave Biogen Idec a heightened review, and Novartis earnings were marred by restructuring charges. Also, the Merck/ Schering Plough Vytorin saga surged on, and a slew of big pharmas were hit by an article that says the efficacy of anti-depressants may be depressingly misrepresented.

First, ZymoGenetics ( ZGEN) shares added $2.01, or 16.9%, to $13.98 after it got the delayed FDA approval for rThrombin, or Recothrom. The product is a plasma-free thrombin, used as a blood clotting agent when control of bleeding by standard surgical techniques is ineffective or impractical.

ZymoGenetics signed a collaboration with Bayer HealthCare Pharmaceuticals in June worth up to $198, and the approval triggers a $40 million milestone payment.

The stock made "Winners and Losers" on Wednesday when it dipped after an analyst initiated a sell rating, questioning whether the product would get approved without further delay.

Recothrom will compete with Omrix Biopharmaceuticals' ( OMRI) Evithrom, a human thrombin product that received FDA approval in August.

Shares of competitor Omrix Biopharmaceuticals fell back 88 cents, or 2.9%, to $29.99 Thursday.

On to a company that had an approval earlier this week, Bank of America analyst William Ho upgraded Biogen Idec ( BIIB) to buy from neutral and raised his price target to $73 a share from $61, based on the company's growth strategy and the recent FDA approval of Tysabri for Crohn's disease.

Notably, Ho said in a report that the new estimates are still less aggressive than the biotechnology company's guidance, assuming there will be 64,000 patients on Tysabri by 2010 rather than the company's guidance of 100,000. And even with his more conservative outlook, he says that the current share price undervalues the company.

Shares rose $1.67, or 2.8%, to $61.66.

Elsewhere, a study in the New England Journal of Medicine is taking a toll on makers of anti-depressants. An article concluded that published studies over-represent trials with positive results, potentially skewing perceptions of efficacy. "Not only were positive results more likely to be published, but studies that were not positive, in our opinion, were often published in a way that conveyed a positive outcome," wrote the authors of "Selective Publication of Antidepressant Trials and Its Influence on Apparent Efficacy."

Ninety-four percent of studies that were published on the antidepressants had positive results, while only 51% of all studies registered with the FDA had positive outcomes.

Some anti-depressant makers with drugs involved in the article's analysis traded down after the research was published both in post-market trading Wednesday and on Thursday. Wyeth ( WYE) was down $1.53, or 3.33%, at $44.61. Eli Lilly ( LLY) was down $1.19, or 2.1% at $54.88, GlaxoSmithKline ( GSK) was down 70 cents, or 1.4%, at $50.89, and Bristol Myers Squibb ( BMY) was down 63 cents, or 2.4%, at 25.19.

All four of those stocks are components of the Amex pharmaceutical index, which was down 6.94, or 2%, to 339.36.

A stock not on that index, Novartis, ( NVS) was also trading a little behind on Thursday. Novartis' year-end results were harmed by a $444 million restructuring charge in the fourth quarter and a $1.4 billion drop in U.S. sales of five drugs throughout the year, although the Swiss drug and vaccine maker also announced a $9.2 billion buyback.

For the year, net sales increased 11% to $38.1 billion. Profits totaled $11.95 billion, vs. $7.2 billion in 2006. Excluding divestments, the company said profit declined 6% to $6.75 billion. Basic annual earnings per share were down 3% to $2.81 from $2.90 the year before.

Shares of the Switzerland-based pharmaceutical company were trading down $1.98, or 3.6%, to $53.46.

And finally, another update on the Merck ( MRK) and Schering Plough ( SGP) Vytorin mess.

To refresh, earlier this week the companies released the long-delayed results of the ENHANCE study which looked at Vytorin, a combination of cholesterol lowering drug Zetia and a statin, in comparison to a statin alone. The results indicated that the more expensive Vytorin did no more to lessen arterial plaque build up than the statin alone, although Vytorin has been shown to significantly lower cholesterol, more so than statins.

Shares took a beating early in the week, but analysts assessed that the effect on stock price was an overreaction to the news. And the American College of Cardiology issued a statement telling patients there was no reason to panic.

So the new information - on Wednesday post-close various news sources reported that members of Congress sent a letter to the companies and also to the FDA indicating that the House of Representatives' Committee on Energy and Commerce and its Subcommittee on Oversight and Investigations are conducting an investigation. Specifically, they are probing withholding of study data and the possible use of misleading statements in direct-to-consumer advertisements for prescription medicines.

Merck was trading down 3.49, or 6%, at $54.84, and Schering Plough was down $1.65, or 7%, to $21.85 on Thursday.

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