On the other hand applying the radioligand DASB, the Neochlorogenic-acid second study failed to detect any effect of Val66Met genotype status on 5-HTT binding. To resolve contradictory results we conducted an imaging genetics study investigating the association between 5-HTT binding using PET with the radiolig and DASB and the Val66Met genotype status in healthy subjects as well as in depressive patients. We also measured 5-HT1A receptor binding in healthy subjects genotyped for Val66Met, in order to resolve two equivocal findings.We hypothesized, that Val66Met impacts on 5HTT binding in patients with major depression and healthy subjects. Furthermore, we hypothesized that significant differences are detected between BDNF genotype status and 5-HT1A binding in healthy subjects. In a voxel-wise analysis as well as in a ROI-based approach, we did not observe significant differences of 5-HT1A-receptor BPND nor of 5-HTT BPND according to BDNF genotype status. There was no interaction between MDD diagnosis or sex and 5-HTT BPND. In the midbrain, weak increases of 5-HTT-BPND in healthy subjects between val-homozygotes and met-carriers were found. Furthermore, weak increases of 5-HTT BPND were observed in the midbrain in val-homozygote healthy subjects compared to valhomozygote MDD patients. There was no association between allelic distribution and major depression. To sum up, all voxel-wise and ROI-based testing yielded negative results and none of the post-hoc tests survived correction. Our results are in concordance with a previous PET study applying DASB in 49 healthy subjects, where the authors neither detected differences in 5-HTT binding in relation to BDNF genotype nor a correlation between blood BDNF levels and central 5-HTT binding. Additionally, no effect on 5-HT2A binding was shown in this work. Here, the authors calculated the radiotracer BPND similar to our study by applying a fully automated reference region model and an automated ROI-delineation. The only other currently published human PET-study investigating the impact of BDNF polymorphisms on 5-HTT binding Magnoflorine-chloride reports differences in men and shows no effect of genotype status on 5-HT1A binding.