Gendle Mathew H, Golding Abbe C
Department of Psychology, Elon University, Elon, North Carolina 27244, USA.
Hum Psychopharmacol. 2010 Aug;25(6):491-9. doi: 10.1002/hup.1139.
Although the serotonin precursor 5-hydroxytryptophan (5-HTP) is marketed as a psychoactive nutritional supplement, knowledge is limited regarding the effects of exogenous 5-HTP on brain activity. This study examined if oral administration of 5-HTP to healthy adults impacted: (1) mood states, as measured by the Profile of Mood States (POMS); and (2) performance on the Iowa Gambling Task (IGT), a measure sensitive to alterations in frontocortical serotonin levels.
A sample of 46 undergraduates participated, and each received either two 50 mg 5-HTP capsules or placebos, and completed the IGT and POMS following an absorption period.
5-HTP did not significantly alter mood states, but did impair performance on the IGT. Specifically, the 5-HTP group performed more poorly than the placebo group during the first 20 trials of the IGT but did not differ from the placebo group on trials 21-100. This suggests that oral 5-HTP specifically impaired decision making under ambiguity but not under risk. Males also performed more poorly on the first 20 trials of the IGT, regardless of treatment group.
Oral 5-HTP is psychoactive at low doses. Decisions made under ambiguity may be differentially sensitive to increased serotonin release or associated reductions in frontocortical dopamine activity.
尽管血清素前体5-羟色氨酸（5-HTP）作为一种精神活性营养补充剂上市，但关于外源性5-HTP对大脑活动影响的了解有限。本研究调查了对健康成年人口服5-HTP是否会影响：（1）情绪状态，通过情绪状态剖面图（POMS）测量；以及（2）爱荷华赌博任务（IGT）的表现，这是一种对额叶皮质血清素水平变化敏感的测量方法。
46名本科生参与了该研究，每人服用两粒50毫克的5-HTP胶囊或安慰剂，并在吸收期后完成IGT和POMS测试。
5-HTP并未显著改变情绪状态，但确实损害了IGT的表现。具体而言，在IGT的前20次试验中，5-HTP组的表现比安慰剂组更差，但在第21 - 100次试验中与安慰剂组没有差异。这表明口服5-HTP特别损害了在模糊情境下而非风险情境下的决策能力。无论治疗组如何，男性在IGT的前20次试验中的表现也更差。
低剂量口服5-HTP具有精神活性。在模糊情境下做出的决策可能对血清素释放增加或额叶皮质多巴胺活性相关降低具有不同的敏感性。
