Specific distribution volumes of 5-HT1A receptor in the stimulation epicenters located in the left and right DLPFC as assessed using [carbonyl-11C]WAY-100635 appeared to be differentially affected by three weeks of bilateral TBS treatment (iTBS over the left and cTBS over the right DLPFC) compared to sham stimulation in a sample of eleven TRD patients. This evidence concerns the gene HTR1A and treatment resistant depression.