Study author Dr. Sanjiv Kumra of the University of Minnesota in Minneapolis recruited 39 children ages 10 to 18 who had already failed to respond to at least two anti-psychotic treatments, to participate in a 12-week, double-blind, randomized study of clozapine or "high dose" olanzapine. High dose refers to doses exceeding package insert recommendations.

The study, published in Biological Psychiatry, found clozapine to be approximately twice as likely as olanzapine to produce a treatment response.

Kumra reported both medications "produced significant weight gain and associated metabolic abnormalities," but without these drugs the result would likely be long-term institutional care or early death.

Additional research will be needed to follow-up on this preliminary finding, Kumra said.