Association of ABCB1 Gene Variants, Plasma Antidepressant Concentration, and Treatment Response: Results from a Randomized Clinical Study

P-glycoprotein, encoded by the ABCB1 gene, functions as an ATP-driven efflux pump in the blood–brain barrier, extruding its substrates and thereby limiting their passage into the brain. ABCB1 polymorphisms predicted antidepressant drug response: Minor allele carriers of SNPs rs2032583 and rs2235015 had higher remission rates than major allele homozygotes. The aim of the current study was to evaluate an ABCB1 genotype-dependent efficacy of a quick dose escalation strategy.