The International Journal of Neuropsychopharmacology

Brief Report

The obesity risk gene FTO influences body mass in chronic schizophrenia but not initial antipsychotic drug-induced weight gain in first-episode patients

Gavin P. Reynoldsa1 c1, Olga O. Yevtushenkoa1, Sarah Gordona1, Belen Arranza2, Luis Sana3 and Stephen J. Coopera1

a1 Department of Psychiatry, Queen's University Belfast, Belfast, UK

a2 Parc Sanitari Sant Joan de Deu, CIBERSAM, Barcelona, Spain

a3 Hospital Sant Joan de Deu, CIBERSAM, Barcelona, Spain


Genetic factors contribute to the individual variability in weight gain caused by several antipsychotic drugs. The FTO gene is associated with obesity in the general population; we have investigated whether a common risk polymorphism (rs9939609) in this gene is associated with antipsychotic drug-induced weight gain and obesity. Two samples were studied: (1) 93 first-episode patients receiving antipsychotic drugs for the first time and having body weight monitored for up to 12 months; (2) 187 chronic patients with schizophrenia assessed for measures of obesity and metabolic dysfunction. No association of FTO genotype with weight gain was found in initially drug-naive patients. The chronically treated patients had a significant association of genotype with body mass index (BMI), reflected in associations with waist circumference, waist:hip ratio and the frequency of central obesity. These findings indicate that FTO genotype has a major effect on body weight determined by BMI in chronically treated patients with schizophrenia.

(Received August 17 2012)

(Reviewed October 03 2012)

(Revised October 23 2012)

(Accepted November 06 2012)

(Online publication December 14 2012)

Key words

  • Antipsychotic drugs;
  • FTO gene;
  • metabolic syndrome;
  • obesity;
  • weight gain


c1 Address for correspondence: Professor G. Reynolds, Biomedical Research Centre, Sheffield Hallam University, Sheffield S1 1WB, UK. Tel.: +44 114 3075 Email: