Association study between vesicle-associated membrane protein 2 gene polymorphisms and fluvoxamine response in Japanese major depressive patients

Background: Vesicle-associated membrane protein 2 (VAMP2) is a key component of the synaptic vesicle docking/fusion machinery and its mRNA reportedly increases in the frontal cortex of rats following chronic antidepressant and electroconvulsive treatment. VAMP2 is therefore thought to be involved in the mechanism of action of antidepressants and may alter their efficacy. The purpose of this study was to investigate whether the VAMP2 gene is associated with clinical responses to a specific antidepressant, fluvoxamine. Methods: A total of 106 patients with major depressive disorder were given fluvoxamine (50-200 mg/day) for 8 weeks and assessed for severity of depression using the Semi-Structured Interview Guide of the Hamilton Depressive Scale (SIGH-D; 17 items) at 0 and 8 weeks. We defined a clinical response as more than a 50% reduction in baseline SIGH-D within 8 weeks, and defined clinical remission as a SIGH-D score of less than 7 at 8 weeks. Genotyping was performed by PCR-RFLP. Results: Analysis of haplotype tagging single nucleotide polymorphisms as well as haplotype analysis did not reveal any significant associations. Conclusion: Our results suggest that the VAMP2 gene is unlikely to play a major role in the efficacy of fluvoxamine.