"Patients and physicians should be aware that psychosis or mania arising during drug treatment of attention-deficit hyperactivity disorder may represent adverse drug reactions, the study's authors wrote in the February issue Pediatrics. -- Children who take medications for attention-deficit hyperactivity disorder (ADHD) may rarely experience some disturbing side effects, such as hallucinations. Government experts revie clinical trials and post-marketing reports of side effects from the commonly prescribed ADHD stimulant medications, such as Concerta, Ritalin and Strattera. It's usually really young kids who are on medications, and once they back off or stop the medications, the sensation is gone," he said. "We see a lot of children on medications here, and I would say maybe one a year or once every two years, we might hear about a child with tactile hallucinations, where kids feel like they have bugs on them. Almost 8 percent of children in the Unite States -- about 4.5 million -- have ever received a. "These reactions are very rare," said Dr. Roy Boorady, director of the psychopharmacology service at the New York University Child Study Center in New York City.

They found that out of every 100 "person-years" of treatment, one or two children will experience serious side effects, such as hallucinations of bugs or snakes.