Higher 5-HT1A receptor binding potential during a major depressive episode predicts poor treatment response:...

Serotonin 1A (5-HT1A) binding potential (BP) as assessed by positron emission tomography (PET) is higher in major depressive disorder (MDD) in association with the higher expressing GG genotype of the 5-HT1A C-1019G polymorphism. We hypothesize that higher 5-HT1A BP and the GG genotype predict remission failure on antidepressant treatment. We determined 5-HT1A BP by PET and 5-HT1A C-1019G genotype in 43 controls and 22 medication-free MDD subjects. MDD was treated naturalistically and remission was defined as >50% reduction and a score of