AbstractThis study investigated the possible association of the MAOA T941G gene variant with differential antidepressant response to mirtazapine and/or paroxetine in 102 patients with major depression (DSM‐IV criteria) participating in a randomized double‐blind controlled clinical trial. Female mirtazapine‐treated patients homozygous for the T‐allele had a significantly faster and better treatment response than TG/GG‐patients. In males, we failed to show an association between MAOA T941G gene variant and mirtazapine response. In the paroxetine‐treated group, there were no significant differences in treatment response between MAOA T941G genotype groups. Time course of response and antidepressant efficacy of mirtazapine, but not paroxetine, seem to be influenced in a clinically relevant manner by this allelic variation within the MAOA gene, at least in female patients. An independent replication of our finding is needed. If replicated, genotyping of this locus could become a promising tool to predict response to mirtazapine treatment in females suffering from major depression. © 2006 Wiley‐Liss, Inc.