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
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.
ADHD researcher William Pelham Jr., PhD, tells WebMD that hallucinations and
similar psychiatric symptoms are well known to clinicians who specialize in
treating children with the disorder.
Pelham is a professor of psychology, pediatrics, and psychiatry at the State
University of New York at Buffalo.
"Off the top of my head, I would say I have seen this in about one out
of every 100 kids I've treated," he says.
But he adds that pediatricians and other clinicians who don't specialize in
ADHD may fail to associate psychotic episodes with stimulant drug use.
He notes that the drugs have also been linked to sudden death in children
with heart problems. It is now recommended that children be evaluated for heart
problems before beginning treatment with ADHD medications.
"The hope is that reports like this one will raise awareness that these
are not benign medications. They are psychoactive drugs with side effects,"