Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria.
Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria.
Transl Psychiatry. 2018 Sep 21;8(1):198. doi: 10.1038/s41398-018-0227-2.
Increased cerebral monoamine oxidase A (MAO-A) levels have been shown in non-seasonal depression using positron emission tomography (PET). Seasonal affective disorder (SAD) is a sub-form of major depressive disorder and is typically treated with bright light therapy (BLT). The serotonergic system is affected by season and light. Hence, this study aims to assess the relevance of brain MAO-A levels to the pathophysiology and treatment of SAD. Changes to cerebral MAO-A distribution (1) in SAD in comparison to healthy controls (HC), (2) after treatment with BLT and (3) between the seasons, were investigated in 24 patients with SAD and 27 HC using [C]harmine PET. PET scans were performed in fall/winter before and after 3 weeks of placebo-controlled BLT, as well as in spring/summer. Cerebral MAO-A distribution volume (V, an index of MAO-A density) did not differ between patients and HC at any of the three time-points. However, MAO-A V decreased from fall/winter to spring/summer in the HC group (F = 4.79, p < 0.050), while SAD showed no change. In addition, BLT, but not placebo, resulted in a significant reduction in MAO-A V (F = 25.96, p < 0.001). This is the first study to demonstrate an influence of BLT on human cerebral MAO-A levels in vivo. Furthermore, we show that SAD may lack seasonal dynamics in brain MAO-A levels. The lack of a cross-sectional difference between patients and HC, in contrast to studies in non-seasonal depression, may be due to the milder symptoms typically shown by patients with SAD.
使用正电子发射断层扫描(PET)已显示非季节性抑郁症患者大脑单胺氧化酶 A(MAO-A)水平升高。季节性情感障碍(SAD)是重度抑郁症的一种亚形式,通常采用亮光疗法(BLT)进行治疗。5-羟色胺能系统受季节和光照的影响。因此,本研究旨在评估大脑 MAO-A 水平与 SAD 病理生理学和治疗的相关性。使用 [C]harmine PET 研究了 24 例 SAD 患者和 27 例健康对照者(HC)中 SAD 与 HC 相比(1)大脑 MAO-A 分布的变化、(2)接受 BLT 治疗后的变化和(3)季节之间的变化。PET 扫描分别在秋季/冬季(治疗前)、冬季/春季(治疗后)和春季/夏季进行。在任何三个时间点,患者和 HC 的大脑 MAO-A 分布体积(V,MAO-A 密度的指标)均无差异。然而,HC 组的 MAO-A V 从秋季/冬季到春季/夏季下降(F=4.79,p<0.050),而 SAD 则没有变化。此外,BLT 而非安慰剂可显著降低 MAO-A V(F=25.96,p<0.001)。这是第一项证明 BLT 对人类大脑 MAO-A 水平具有体内影响的研究。此外,我们表明 SAD 可能缺乏大脑 MAO-A 水平的季节性动态。与非季节性抑郁症的研究相比,患者与 HC 之间缺乏横断面差异,这可能是由于 SAD 患者的症状通常较轻。