Shares for Eli Lilly and Johnson & Johnson dropped more than 1% yesterday after a US study found new antipsychotics were no more effective than older conventional ones in treating child and adolescent schizophrenia.

The study, funded by the National Institutes of Health’s National Institute of Mental Health, also found newer medicines may lead to more metabolic side effects than their older counterparts.

More than 110 youths between the ages of eight and 19, who were diagnosed with early onset schizophrenia spectrum disorder, were randomly assigned eight weeks of either Zyprexa (olanzapine) or Risperdal (risperidone), new generation atypical antipsychotics manufactured by Eli Lilly and J&J respectively. Other children were randomly assigned older conventional antipsychotics Moban (molindone) plus benztropine.

Results showed that after eight weeks of treatment 50% of the children taking molindone improved, 46% taking risperidone improved and 34% taking olanzapine improved. Children taking olanzapine or risperidone improved within the first two weeks and children on the older drug improved within three weeks.

Children taking the newer antipsychotics saw considerable weight gain over the eight-week period, while the children on the older medication gained no weight.

The olanzapine group also showed increases in cholesterol levels and other metabolic disruptions that may have become dangerous prompting the safety review board to end the olanzapine arm of the study early.

“Schizophrenia and schizophrenia-related disorders are rare in childhood, but when they do occur, those afflicted generally have more severe symptoms and a worse prognosis than those who develop the disorder in adulthood,” said NIMH Director Thomas Insel.

“The newer atypical antipsychotics are often used to treat these children, but until now, it has been unclear how effective and safe they really are in children. The side effects of the newer medications should be factored into making treatment decisions.”

Lead author Kinmarie Sikich agreed. “Atypical antipsychotics are commonly used to treat kids with EOSS, but these results question the wisdom of that approach.”

“They also remind us that we need to develop safer, more effective medication to treat these children, given the limited effectiveness of both the atypical and the conventional medications.”

Currently, Zyprexa is only approved for use in adults but Eli Lilly does have an application pending with the US Food and Drug Administration to expand the medication to children aged 13 and older. Risperdal was approved in the US last year for treating adolescents.

Both companies are facing lawsuits in regards to alleged inappropriate marketing of the drugs.

Last year, sales for Zyprexa and Risperdal reached $4.8 billion and $3.4 billion respectively.