[Studies on Monoamine Transporter Occupancy of Antidepressants using PET: Focusing on SERT and NET]

Monoamine transporter occupancy of antidepressants in the brain can be measured by positron emission tomography. For antidepressive effects to appear, serotonin transporter (SERT) occupancy should rise to 80% or higher. Despite a recent increase in the number of reports on norepinephrine transporter (NET) occupancy, estimating the threshold level of NET occupancy required for antidepressive effects is difficult based on the analysis of NET alone. Therefore, studies should be conducted on NET occupancy required for a valid treatment, including an ideal balance between SERT and NET occupancy. (Received 24 September 2020; Accepted December 18, 2020; Published June 1, 2021).