Non-displaceable binding potential changes of striatal dopamine D2 receptors in patients with first-episode major depressive disorder and the correlation with clinical features / 中华核医学与分子影像杂志

ABSTRACT

Objective To observe non-displaceable binding potential (BPND) changes of striatal dopamine D2 receptors(SDDR) in patients with first-episode major depressive disorder (MDD) using 11C-Raclopride PET/CT,and to analyze the relationship between BPND and Hamilton rating scale for depression (HAM-D).Methods From December 2014 to December 2015,patients with first-episode MDD and age/gender-matched healthy controls underwent brain MRI and 11C-Raclopride PET/CT in this prospective study.BPND of bilateral SDDR was calculated by molecular imaging and kinetic analysis toolbox (MIAKAT).BPND changes of bilateral SDDR and their relationship with HAM-D score were analyzed.Paired t test,two-sample t test and Pearson correlation analysis were used.Results A total of 20 MDD patients (8 males,12 females,average age (32.80±9.76) years) and 20 healthy controls (9 males,11 females,average age(29.25±6.93) years) were enrolled in this study.The 11C-Raclopride uptake in brain tissue of the MDD group and control group were mainly distributed in bilateral striatum,and very few 11C-Raclopride was distributed in bilateral cerebral cortex and cerebellum.In MDD group,the BPND level of bilateral SDDR had no statistical differences(t values 0.69,0.35,both P>0.05),and similar results were found in the control group(t values 0.28,0.24,both P>0.05).Compared with the control group,however,the MDD group had lower BPND level of bilateral SDDR(t values 3.13-4.41,all P<0.05).The BPND of bilateral caudate nucleus and/or putamen D2 receptors was correlated with HAM-D total score,anxiety/somatization factor score,cognitive impairment factor score,retardation factor score and sleep disturbance factor score(r values from-0.688 to-0.453,all P<0.05).Conclusions The binding potential of SDDR in patients with first-episode MDD is declined,and the BPND level of SDDR is correlated with symptoms of depression.The abnormality of SDDR may be an important molecular mechanism of the abnormality of midbrain-striatal dopamine reward circuits in MDD patients.