Reports of psychosis or mania in children were associated with all of the increasingly popular drugs used to treat attention deficit hyperactivity disorder, federal health officials say in documents released as an advisory panel prepares to consider stronger warning labels.

The scientific panel meets Wednesday.

The reviews show that the adverse events, particularly hallucinations, can occur in some 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 HDHD 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 Company.

FDA officials say patients and doctors should be aware that the small number of 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. And in many children, the events ceased once they stopped taking the drugs — and resumed if they restarted.

"The predominance in young children of hallucinations, both visual and tactile, involving insects, snakes and worms is striking, and deserves further evaluation," FDA officials said in a March 3 memorandum included in the briefing documents.

The FDA's pediatric advisory committee meets Wednesday to examine whether the labels of the drugs should be revised to further warn not only of potential psychiatric problems but cardiovascular issues — like heart attack, stroke and hypertension — as well.

McNeil Consumer & Specialty Pharmaceuticals said in the 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.

Wednesday's FDA committee will be the second in as many months to take up the issue of whether stronger warning labels are merited. The warnings had been under study by the agency since last year.

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

In February, the FDA's Drug Safety and Risk Management advisory committee voted to recommend adding so-called "black-box" warnings to stimulants used to treat ADHD. A black-box is the most serious type of warning label a prescription drug can carry. In this case, it would alert doctors, patients and parents of the uncertainty regarding the risk that most of the drugs may pose to the cardiovascular system.

The recommendation excluded both Adderall, which has included such a warning since 2004, and Strattera, which does however bear a warning about suicidal thoughts. That drug is both "safe and effective," Lilly said.

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.