Reuters: Drugs for attention deficit hyperactivity disorder can cause children to have hallucinations even when taken as directed, U.S. government researchers said on Monday.

U.S. Food and Drug Administration researchers analyzed data from 49 clinical studies conducted by makers of the drugs and found they can cause psychosis and mania in some patients, including some with no obvious risk factors. In some cases, children hallucinated that worms, bugs or snakes were crawling on them.

"Patients and physicians should be aware of the possibility that psychiatric symptoms consistent with psychosis or mania" might arise in the course of treatment, Dr. Andrew Mosholder and colleagues wrote in the journal Pediatrics.

Their analysis provides fresh detail about known risks of the drugs, which include Novartis AG's Ritalin and Focalin XR, Shire Plc's Adderall XR and Daytrana patch, Johnson & Johnson's Concerta, Eli Lilly and Co's Strattera and Celltech Pharmaceuticals Inc's Metadate CD.

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