Many studies suggest an association of the serotonin transporter gene polymorphism (5HTTLPR) long allele with better antidepressant treatment response than the short allele. However, there is controversy over these findings. We hypothesized that if the long allele is associated with a better outcome, we would find fewer inpatients with the long allele compared with the short allele. Chart review identified 925 depressed inpatients and 201 outpatients genotyped for 5HTTLPR. The sample was primarily White (>90%). We tested potential departures from Hardy–Weinberg equilibrium for each sample. We analyzed three independent sets of inpatient samples separately and combined, a White subgroup of 791 patients of the total 925 inpatients, and 201 outpatients. There was no departure from Hardy–Weinberg equilibrium with any of these samples. We also compared 5HTTLPR genotype prevalence between 925 inpatients and 201 outpatients, which showed no statistically significant difference.
aDepartment of Psychiatry, University of Iowa, Iowa City, Iowa
bDepartment of Psychiatry and Psychology, Mayo Clinic, Rochester, Minnesota, USA
Correspondence to Gen Shinozaki, MD, Department of Psychiatry, University of Iowa, Iowa City, IA 52242, USA Tel: +1 319 356 2230; fax: +1 319 352 6482; e-mail: firstname.lastname@example.org
Received November 25, 2012
Accepted October 16, 2013