Department of Neuropsychiatry, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, Stockholm, Sweden.
Psychiatry Clin Neurosci. 2020 Aug;74(8):424-430. doi: 10.1111/pcn.13020. Epub 2020 May 26.
Dysfunction of dopaminergic neurons in the central nervous system is considered to be related to major depressive disorder (MDD). Especially, MDD in geriatric patients is characterized by anhedonia, which is assumed to be associated with reduced dopamine neurotransmission in the reward system. Dopamine transporter (DAT) is considered to reflect the function of the dopamine nerve system. However, previous DAT imaging studies using single photon emission computed tomography or positron emission tomography (PET) have shown inconsistent results. The radioligand [ F]FE-PE2I for PET enables more precise evaluation of DAT availability. Hence, we aimed to evaluate the DAT availability in geriatric patients with MDD using [ F]FE-PE2I.
Eleven geriatric patients with severe MDD and 27 healthy controls underwent PET with [ F]FE-PE2I, which has high affinity and selectivity for DAT. Binding potentials (BP ) in the striatum (caudate and putamen), nucleus accumbens (NAc), and substantia nigra were calculated. BP values were compared between MDD patients and healthy controls.
MDD patients showed significantly lower DAT BP in the NAc (P = 0.009), and there was a trend of lower BP in the putamen (P = 0.032) compared to controls.
We found low DAT in the NAc and putamen in geriatric patients with severe MDD, which could be related to dysregulation of the reward system.
中枢神经系统中多巴胺能神经元功能障碍被认为与重度抑郁症（MDD）有关。特别是老年患者的 MDD 表现为快感缺失，这被认为与奖励系统中多巴胺神经传递减少有关。多巴胺转运体（DAT）被认为反映了多巴胺神经系统的功能。然而，使用单光子发射计算机断层扫描或正电子发射断层扫描（PET）的先前 DAT 成像研究结果不一致。用于 PET 的放射性配体[ F]FE-PE2I 可以更精确地评估 DAT 的可用性。因此，我们旨在使用[ F]FE-PE2I 评估患有 MDD 的老年患者的 DAT 可用性。
11 名患有严重 MDD 的老年患者和 27 名健康对照者接受了[ F]FE-PE2I 的 PET 检查，该检查对 DAT 具有高亲和力和选择性。计算纹状体（尾状核和壳核）、伏隔核（NAc）和黑质中的结合势（BP）。比较 MDD 患者和健康对照组之间的 BP 值。
与对照组相比，MDD 患者 NAc 中的 DAT BP 明显降低（P = 0.009），而壳核中的 BP 也有降低的趋势（P = 0.032）。
我们发现严重 MDD 老年患者的 NAc 和壳核中 DAT 水平较低，这可能与奖励系统的失调有关。
