Reduced midbrain serotonin transporter availability in drug-naïve patients with depression measured by SERT-specific [(123)I] nor-beta-CIT SPECT imaging.

Earlier results have indicated that serotonin transporter (SERT) availability is altered in major depression. We examined SERT density with a more serotonin-specific ligand and with a larger number of patients than in previous studies. Twenty-nine antidepressant-naïve patients with major depressive disorder (MDD) and 19 healthy age- and sex-matched controls were studied with SPECT using [(123)I] nor-beta-CIT as a ligand. The patients had a significantly lower (-10%) binding potential in the midbrain region than controls. No correlation with depression severity was found. These findings indicate that SERT availability in the midbrain area is reduced in depression, and that interindividual variation is considerable in both patients and controls.