Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy.
Sleep Disorders Center, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy.
Eur J Neurol. 2020 May;27(5):779-786. doi: 10.1111/ene.14179. Epub 2020 Mar 13.
Several studies have indicated that altered serotonergic neurotransmission may contribute to non-motor features commonly associated with Parkinson's disease (PD) such as apathy and depression. 5-hydroxytryptophan (5-HTP) is the intermediate metabolite of L-tryptophan in the production of serotonin. To date, there has been inconsistent research on the use of 5-HTP in PD. The purpose of this study was to compare the effects of 5-HTP with those of placebo on apathy and depressive symptoms in patients with PD.
A single-center, randomized, double-blind placebo-controlled cross-over trial was employed; 25 individuals were subsequently enrolled into the study. Patients received placebo and 50 mg of 5-HTP daily over a period of 4 weeks. For the assessment of efficacy on depressive and apathy symptoms the Beck Depression Inventory-II (BDI-II), Hamilton Depression Rating Scale (HDRS) and Apathy Scale (AS) were respectively administered at screening, baseline and weeks 4, 8, 12 and 16. Primary efficacy outcomes were the comparison of 5-HTP to placebo in mean change from baseline to weeks 4, 8, 12 and 16 in total score on the AS, BDI-II and HDRS.
Repeated-measures analysis revealed a significant improvement of depressive symptoms during the 50-mg 5-HTP treatment compared with placebo as assessed by the HDRS. No effect of 5-HTP was seen on apathy symptoms assessed by the AS.
This study provides preliminary evidence of clinical benefit of 5-HTP for treating depressive symptoms in PD. Larger studies with a longer treatment duration are needed to corroborate these early findings.
多项研究表明，血清素能神经递质的改变可能与帕金森病（PD）的非运动症状有关，如淡漠和抑郁。5-羟色氨酸（5-HTP）是 L-色氨酸生成血清素的中间代谢产物。迄今为止，关于 5-HTP 在 PD 中的应用的研究结果并不一致。本研究旨在比较 5-HTP 与安慰剂对 PD 患者淡漠和抑郁症状的影响。
采用单中心、随机、双盲、安慰剂对照交叉试验；随后有 25 名患者入组研究。患者接受安慰剂和 50mg 5-HTP 治疗，为期 4 周。为评估对抑郁和淡漠症状的疗效，分别在筛查、基线和第 4、8、12 和 16 周时使用贝克抑郁量表 II（BDI-II）、汉密尔顿抑郁评定量表（HDRS）和淡漠量表（AS）进行评估。主要疗效结局为比较 5-HTP 与安慰剂在 AS、BDI-II 和 HDRS 总分从基线到第 4、8、12 和 16 周的平均变化。
重复测量分析显示，与安慰剂相比，5-HTP 50mg 治疗可显著改善 HDRS 评估的抑郁症状。AS 评估的淡漠症状未见 5-HTP 的作用。
本研究为 5-HTP 治疗 PD 抑郁症状的临床获益提供了初步证据。需要进行更长治疗时间的更大规模研究来证实这些早期发现。
