Title screen

Background:Brain-derived neurotrophic factor (BDNF) is associated with response to antidepressant drugs inmood and anxiety disorders. Prolactin (PRL) is a pituitary hormone with behavioural effects, acting as a neu-rotrophic factor within the brain and may be involved in antidepressant response.Objectives:To investigate the relationship betweenBDNFandPRLgenotypes with antidepressant drug response.Methods:Prospective inception cohort of 186 Russian treatment-free participants (28 men and 158 women)between 18 and 70 years clinically diagnosed with depressive disorder who initiated antidepressant medication.DNA polymorphisms were genotyped forPRLrs1341239,BDNFrs6265 and rs7124442. Primary outcome wasmeasured by differences in Hamilton Depression Rating Scale (ΔHAM-D) scores between baseline/week two,week two/week four, and baseline/week four. Linear regression and independentt-test determined the sig-nificance between polymorphisms andΔHAM-D.

Results: Comparisons between genotypes did not reveal any significant differences in scores during thefirst twoweeks of treatment. In the latter two weeks, BDNFrs7124442 homozygous C patients responded significantlyworse in comparison to homozygous T patients during this period. Further analysis within women and in post-menopausal women found a similar comparison between alleles. Limitations: Study lasted four weeks, which may be considered short to associate genuine antidepressant effects.Conclusions:Patients taking tricylic antidepressants were noted to have a significant improvement inΔHAM-Dcompared to patients taking SSRIs. Homozygous CBDNFrs712442 patients were found to respond significantlyworse in the last two weeks of treatment.