ADHD Drugs: Hallucinations Not Uncommon
FDA Examines Incidence of Psychotic Symptoms in Children Taking ADHD Medications
Jan. 26, 2009 -- Treatment-related hallucinations and other psychotic symptoms in children with attention deficit hyperactivity disorder (ADHD) may be more common than previously thought, FDA officials report in the latest issue of the journal Pediatrics.
In an earlier investigation, FDA researchers identified more than 850 separate incidences of hallucinations and other psychotic episodes among children taking stimulants used to treat ADHD.
The investigation prompted federal officials to require new labeling on the drugs, including Ritalin LA, Concerta, Adderall XR, Focalin, Focalin XR, Metadate CD, Daytrana, and Strattera, warning of possible psychiatric side effects.
An estimated 2.5 million children and teens take these and other stimulant-based medications to treat ADHD symptoms.
Nearly half of the cases of hallucination and other psychiatric side effects reviewed by FDA researchers involved children younger than age 11.
And in more than nine out of 10 cases, the children had no reported history of psychiatric events.
Bugs, Worms, and Snakes
Hallucinations involving insects, snakes, or worms were among the most commonly reported psychiatric events among children and teens, FDA medical epidemiologist and drug safety expert Kate Gelperin, MD, MPH, tells WebMD.
"Some children described feeling a sensation of bugs or worms crawling on their skin," she says.
One case detailed in the report involved a 12-year-old boy with cerebral palsy who said he saw roaches surrounding him two hours after taking an ADHD drug containing methylphenidate. The hallucination lasted several hours, recurred when the boy took an additional dose of the drug, but stopped altogether when the drug was discontinued.
An analysis of 49 randomized clinical trials found that for every 100 children who take ADHD drugs for a year, between one and two experience a drug-related psychotic event.
But in the Pediatrics report, the FDA researchers conclude that this estimate is probably low, in part because the clinical trials often excluded children with a history of adverse reactions to ADHD drugs.
"Patients and physicians should be aware of the possibility that psychiatric symptoms consistent with psychosis or mania, when they arise in the course of drug treatment of ADHD, may represent adverse drug reactions," the FDA researchers write.