Three of the four groups had never previously taken atypical antipsychotics. Different groups were treated with drugs such as olanzapine, risperidone, aripiprazole or quetiapine, and compliance was monitored to ensure the treatment regime was followed. Weight and other metabolic-related measures were taken at the start and during treatment.
A genome-wide association study was conducted on pediatric patients by the study's lead researcher, Dr. Anil Malhotra, at the Zucker Hillside Hospital in Glen Oaks, NY. In this type of study, variations are sought across a person's entire set of genes to identify those associated with a particular trait. The result pointed to the MC4R gene.
This gene's role in antipsychotic-induced weight gain had been identified in a CAMH study published earlier this year in The Pharmacogenomics Journal, involving Drs. Mller and Kennedy, and conducted by PhD student Nabilah Chowdhury. They found a different variation on MC4R that was linked to the side-effect.
For both studies, CAMH researchers did genotyping experiments to identify the single changes to the sequence of the MC4R gene known as single nucleotide polymorphisms (SNPs) related to the drug-induced weight gain side-effect.
The MC4R gene encodes a receptor involved in the brain pathways regulating weight, appetite and satiety. "We don't know exactly how the atypical antipsychotics disrupt this pathway, or ho
|Contact: Michael Torres|
Centre for Addiction and Mental Health