Federal health officials on Wednesday sought strengthened warnings of rare but serious risks, including heart attacks and hallucinations, associated with popular drugs for attention deficit hyperactivity disorder.

The Food and Drug Administration asked its pediatric advisory committee to review reports of those potential risks and then recommend how to relay that information to the public. The agency has struggled since last year with that latter task.

"This is really the crux of where we are trying to go," Dr. Dianne Murphy, director of the FDA's office of pediatric therapeutics, told the panel Wednesday.

Last month, the FDA's Drug Safety and Risk Management advisory committee voted to recommend adding"black-box" warnings to stimulants used to treat ADHD, alerting doctors, patients and parents of the uncertainty regarding the risk the drugs may pose to the cardiovascular system. The warnings are the most serious that prescription drugs may bear.

The FDA is not required to follow the recommendations of its advisory committees, but usually does.

The latest reviews show that psychosis or mania can occur in some juvenile patients at normal doses of any ADHD drug. The reviews included roughly 90 studies of the drugs as well as reports from doctors, parents and others.

The ADHD drugs include Ritalin, manufactured by Novartis Pharmaceuticals Corp. and in generic form by other companies; Adderall, made by Shire Pharmaceuticals Inc.; and Strattera, produced by Eli Lilly and Co.

FDA officials say patients and doctors should be aware that the small number of psychiatric events could represent side effects of the drugs, although they cannot point to a definitive link. However, they noted a "complete absence" of similar reports in children treated with dummy pills during dozens of clinical trials of the drugs. In many children, the events ceased once they stopped taking the drugs — and resumed in some once they restarted.

McNeil Consumer & Specialty Pharmaceuticals said in briefing documents that it is customary to weigh the "therapeutic benefits and potential risks" of treatment and warned of the negative effects of leaving ADHD untreated. The unit of Johnson & Johnson makes Concerta, a long-acting form of methylphenidate, the drug in Ritalin.

A third FDA panel is to consider on Thursday an application by Cephalon Inc. to sell its sleep-disorder drug Provigil, or modafinil, as an ADHD treatment for children.

The FDA wants members of its psychopharmalogic drugs advisory committee to weigh that request, including whether serious skin rashes seen in children treated with modafinil should merit special warnings, follow-up studies and implementation of a plan to limit the risk.

In the United States, nearly 3.3 million people age 19 and younger used an ADHD drug in 2005, according to Medco Health Solutions Inc., a prescription drug benefit program manager.