NEW YORK (CNNMoney.com) - The FDA will scrutinize the use of ADHD drugs in children this week and possibly require a new warning label for psychiatric problems and heart attack risks.

The $2 billion market for ADHD seems to be locked in a tug-of-war between the intense need of the American market and the growing fallout from negative reports. Investors and parents have heard a slew of negative news about ADHD drugs, including reports of heart attack risks last year that caused the market's lead drug, Adderall XR, to be temporarily pulled from the market in Canada.

In February, an FDA advisory committee recommended that all ADHD drugs carry a "black box," the most serious type of warning, regarding heart attack risks.

On Wednesday, the Food and Drug Administration's pediatric advisory committee will discuss "adverse reactions," including risks of psychiatric problems and heart attacks, to various drugs prescribed for children for attention deficit hyperactivity disorder. The committee is likely to take a non-binding vote on some form of action regarding the drugs. The FDA follows the advice of its advisors most of the time.

The top-selling drug to appear on the committee's roster is Adderall XR, a drug from British drug maker Shire Pharmaceuticals (Research) with $730 million in 2005 sales and the market share leader. Other ADHD drugs include Strattera from Eli Lilly & Co. (down $0.07 to $57.35, Research), Concerta from Johnson & Johnson (down $0.00 to $60.48, Research), and the generic drug Ritalin from Novartis (down $0.51 to $55.74, Research).

Jonathan Senior, analyst for Evolution Securities, said the committee might decide that Adderall XR needs a "black box" label, the most serious type of warning, for suicide risks. But Senior said he didn't think that new warnings would deflate sales, noting that ADHD prescriptions grew 5 percent in the U.S. over the last 12 months.

"There's a lot of noise around these products, but that doesn't seem to have any impact on prescriptions," said Senior. "People are well aware of these risks. Doctors are still prescribing them and patients are still using them and I don't expect that to change after the committee."

In 2005, a Canadian health care agency ordered that Adderall XR be pulled from the market because of sudden unexplained deaths in children. However, the numbers of deaths were small and Adderall XR was not directly implicated. The drug was returned to shelves six months later.

Senior rates Shire a "sell" because of a completely separate issue: He believes that its P/E ratio of 23 means that it is overpriced, especially considering the threat of generic pressure to Adderall XR. Shire is trying to alleviate that threat by crafting a deal with generic drug manufacturer Barr Laboratories (up $2.32 to $65.85, Research).

Shire spokesman Matt Cabrey said Adderall XR already contains a "black box" warning about the misuse of amphetamines leading to risks of sudden death, even though no link has been established between ADHD drugs and sudden death. Also, he said the drug packaging already includes a warning about psychiatric risks.

"We believe that the Adderall XR label appropriately warns of the risk related to psychosis as a possible adverse event," said Cabrey

Another analyst, who did not wish to be named, said market growth for ADHD drugs is slowing as a result of "increasing numbers of scary stories," and that the 5 percent market growth over the last year is weak in comparison to the previous year's 20 percent growth. Nonetheless, he felt that the market has a strong foundation in the United States, and will continue to be viable even with its troubled reputation.

"I think [the FDA committee meeting] will be, to a certain degree, a storm in a teacup," said the analyst. "There's nothing else for children to take, so they will take it. There's a trend towards pharmaceutical nanny, especially in the U.S."

An experimental ADHD drug, Sparlon from Cephalon (down $0.04 to $72.13, Research), is being considered by a separate FDA advisory committee on Thursday as to whether it should be approved despite reports of suicide risks. Sparlon contains the same active compound as Cephalon's stimulant Provigil, which totaled $513 million in 2005 sales. Cephalon has seen its stock price drop more than 10 percent since March 15, when Sparlon was included on the FDA committee list.

Hamed Khorsand, analyst for BWS Financial, said there is at least a 50 percent chance that Sparlon will get a positive vote from the committee and will eventually be approved by the FDA, though it might get a "black box" warning about suicide risks. Khorsand noted that Cephalon's future depends heavily on Sparlon's approval, as it would add $400 million to $600 million in annual sales to a company that totaled $1.2 billion in 2005 sales.

Aaron Gal, analyst for Sanford Bernstein, also said that Sparlon will probably be approved, with annual sales in the hundreds of millions of dollars.

"I think there will be some warning about the use of this drug," said Gal. "The question is how strong the warning will be in relation to other drugs."

The analysts interviewed for this story do not own shares in the companies mentioned here.

To read about a skin patch for ADHD, click here.