No Data Supporting Antipsychotic Drug for Low-IQ Kids With ADHD

A new Cochrane review finds no evidence to support the use of risperidone to treat attention- deficit/hyperactivity disorder (ADHD) in people with intellectual disabilities, even though the review authors say this is a common prescribing pattern.

Risperidone, or Risperdal, is a second-generation antipsychotic drug. Long-term use of these drugs is associated with serious side effects, including weight gain and increased risk for type 2 diabetes.

“People who have intellectual disability are more likely to receive treatment with second- generation antipsychotics for ADHD,” said lead review author Dr. Alex Thomson. “Doctors should be aware that there is no research to demonstrate the effectiveness of risperidone for ADHD in people with intellectual disability, and should carefully monitor each case and consider alternative treatments before trying risperidone.”

Laurel Leslie, M.D., an associate professor at Tufts University School of Medicine whose research centers on pediatric mental health, concurred: “This study demonstrates that we have a gap between what we’re doing clinically and what we have any research evidence for. It’s an important study, as it highlights the need for careful consideration of how we treat children’s mental health issues.” Leslie has no affiliation with the Cochrane review.

Thomson’s research group did not find one study that met their criteria for inclusion among more than 2,000 studies that they initially identified. The group analyzed 15 studies in depth, but ultimately rejected them all.

“Patients with intellectual disability and their families should be aware that without firm scientific evidence for risperidone’s effectiveness as a treatment for ADHD in this group, doctors can only prescribe on a case-by-case basis and such treatment should be regularly reviewed,” said Thomson, an academic clinical fellow with the Institute of Psychiatry at Kings College in London.

ADHD, one of childhood’s commonest psychiatric ills, fosters inattention, excess activity and impulsivity. An IQ below 70 with significant impairments in functioning is the criterion for intellectual or mental disability (formerly called mental retardation). Researchers estimate that at least 15 percent of people with severe intellectual disability also have ADHD.

Thomson and his colleagues searched all of the leading medical databases for randomized controlled trials, published and unpublished in any language, in which children or adults who had both an intellectual disability and ADHD underwent treatment with risperidone. They also contacted pharmaceutical companies and experts in the field for relevant studies, published and unpublished.

The researchers cite three previous studies, which indicated that among people with an intellectual disability, symptoms of ADHD are more common, serious and enduring than they are among people of normal intellect. Another earlier study suggested that ADHD symptoms are less responsive to medications in these patients, who might be more prone to side effects.