Altered serotonin and dopamine transporter availabilities in brain of depressed patients upon treatment

Altered SERT and DAT availabilities during treatment with escitalopram were investigated with [ 123 I]2β-carbomethoxy-3β-(4-iodophenyl)tropane (β-CIT) SPECT in a series of patients fulfilling the criteria for unipolar major depressive disorder (MDD). 27 patients (10 m, 42716 y) with diagnosis of MDD were recruited for the study. All patients underwent neuropsychiatric testing for assessment of Hamilton Depression (HAM-D) and Beck Depression Inventory (BDI) scores. At baseline, [ 123 I]β-CIT SPECT recordings were acquired 4 h (SERT-weighted) and 20–24 h p.i (DATweighted). Follow-up scans and neuropsychiatric testing were performed after six weeks of stable escitalopram medication. Voxel-wise parametric maps of specific/ non-specific ratios-1 (� BPND) were calculated. At baseline, DAT-weighted BPND was 5.0670.81 in striatum and SERTweighted BPND was 0.9470.18 in thalamus. There were significant negative correlations with age for DAT in striatum (R= � 0.60; po0.01) and SERT in thalamus (R= � 0.45; po0.05). Under SSRI treatment there was an apparent 42% occupancy of SERT in thalamus (po0.0001), whereas DAT availability increased significantly by 20% in striatum (po0.001); higher apparent SERT occupancy in thalamus was associated with lesser DAT increase in striatum (R= � 0.62;