Over 30 per cent of children and teenagers put weight on after taking their initial doses of some of the major antipsychotic drugs available on the market, according to a new US study issued on October 28th 2009. In some instances, rapid weight gain took place over periods of less than three months - the children's new weights putting them in either the obese or overweight categories.

Those behind the report have called on GPs to exercise caution when issuing out antipsychotic drug prescriptions to children, and to monitor their progress whilst they remain on the prescriptions.

Child Psychosis

Four drugs were assessed as part of this child psychosis study. These were:

• Risperidone (marketed as Risperdal)
• Olanzapine (marketed as Zyprexa)
• Aripiprazole (marketed as Abilify)
• Quetiapine (marketed as Seroquel)

272 children/teenagers were studied, whose ages ranged between four and 19 years old. All of them had pre-existing medical conditions such as schizophrenia, bipolar disorder or behavioural disorders, and all were looked at by a group of researchers based at two medical centres at New York - Feinstein Institute for Medical Research and Zucker Hillside Hospital.

Antipsychotic Treatments

Eleven weeks after the first doses of these antipsychotic treatments had been prescribed, all of them were seen to have had an effect on the children's weights, as detailed below.

• Risperdal produced an average weight increase of 3.5 kilograms, or 7.7 pounds
• Zyprexa produced an average weight increase of 8.5 kilograms, or 18.7 pounds
• Abilify produced an average weight increase of 4.4 kilograms, or 9.7 pounds
• Seroquel produced an average weight increase of 6.1 kilograms, or 13.4 pounds

Child Weight Increases

In all, major child weight increases were recorded in up to 36 per cent of those taking part, but how these drugs caused the weights to go up varied, according to head scientist Dr Christoph Correll. Zyprexa caused the most severe weight increases, and triggered significant metabolic shifts too like increased cholesterol/blood sugar levels - opening up the possibility of future heart-related conditions. Abilify - on the other hand - didn't increase blood sugar or cholesterol.

Of the four drugs tested, only two are approved for use in children - Abilify and Risperdal. The other two were recommended by a US FDA (Food and Drug Administration) panel four months ago, but the administration is yet to implement these recommendations.