Shaw K, Turner J, Del Mar C
School of Population Health, University of Queensland, Public Health Building, Herston Rd, Herston, Queensland, Australia, 4006.
Cochrane Database Syst Rev. 2002(1):CD003198. doi: 10.1002/14651858.CD003198.
5 Hydroxytryptophan (5-HTP) and tryptophan are so-called natural alternatives to traditional antidepressants, used to treat unipolar depression and dysthymia.
To determine whether 5-HTP and tryptophan are more effective than placebo, and whether they are safe to use to treat depressive disorders in adults.
Trials were searched in computerized general (Medline, Psychlit, and Embase) and specialized databases (Cochrane Controlled Clinical Trials Register, Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trial Register); by checking reference lists of relevant articles; by handsearching relevant specialist journals; and by contacting relevant authors where appropriate. Publications in all languages were sought.
Trials were included if they were randomized, included patients with unipolar depression or dysthymia, compared preparations of 5-HTP or tryptophan with placebo, and included clinical outcomes assessed by scales assessing depressive symptoms.
Data was extracted independently by the three reviewers, onto data collection forms. Inclusion criteria were applied to all potential studies independently and a coefficient of agreement (Kappa) was calculated for them. Disagreement was resolved by reaching consensus. Trial quality was scored according to risk of bias. Analysis for 5-HTP and tryptophan were combined due to the small number of included trials.
108 trials were located using the specified search strategy. Of these, only two trials, involving a total of 64 patients, were of sufficient quality to meet inclusion criteria. The available evidence suggests these substances were better than placebo at alleviating depression (Peto Odds Ratio 4.10; 95% confidence interval 1.28-13.15; RD 0.36; NNT 2.78). However, the evidence was of insufficient quality to be conclusive.
REVIEWER'S CONCLUSIONS: A large number of studies appear to address the research questions, but few are of sufficient quality to be reliable. Available evidence does suggest these substances are better than placebo at alleviating depression. Further studies are needed to evaluate the efficacy and safety of 5-HTP and tryptophan before their widespread use can be recommended. The possible association between these substances and the potentially fatal Eosinophilia-Myalgia Syndrome has not been elucidated. Because alternative antidepressants exist which have been proven to be effective and safe the clinical usefulness of 5-HTP and tryptophan is limited at present.
5-羟色氨酸（5-HTP）和色氨酸是传统抗抑郁药所谓的天然替代品，用于治疗单相抑郁症和心境恶劣障碍。
确定5-HTP和色氨酸是否比安慰剂更有效，以及它们用于治疗成人抑郁症是否安全。
在计算机化的综合数据库（医学索引、心理学文摘数据库和荷兰医学文摘数据库）和专业数据库（Cochrane对照临床试验注册库、Cochrane协作抑郁、焦虑和神经症对照试验注册库）中检索试验；通过查阅相关文章的参考文献列表；通过手工检索相关专业期刊；并在适当时联系相关作者。检索所有语言的出版物。
如果试验是随机的，纳入单相抑郁症或心境恶劣障碍患者，将5-HTP或色氨酸制剂与安慰剂进行比较，并包括通过评估抑郁症状的量表评估的临床结局，则纳入试验。
三位评价者独立将数据提取到数据收集表上。纳入标准独立应用于所有潜在研究，并计算它们的一致性系数（卡帕）。通过达成共识解决分歧。根据偏倚风险对试验质量进行评分。由于纳入试验数量较少，对5-HTP和色氨酸的分析合并进行。
使用指定的检索策略检索到108项试验。其中，只有两项试验，共涉及64名患者，质量足以满足纳入标准。现有证据表明，这些物质在缓解抑郁方面优于安慰剂（Peto比值比4.10；95%置信区间1.28 - 13.15；风险差0.36；需治疗人数2.78）。然而，证据质量不足以得出结论。
大量研究似乎涉及了研究问题，但很少有质量足以可靠的。现有证据确实表明这些物质在缓解抑郁方面优于安慰剂。在推荐广泛使用之前，需要进一步研究来评估5-HTP和色氨酸的疗效和安全性。这些物质与潜在致命的嗜酸性粒细胞增多-肌痛综合征之间的可能关联尚未阐明。由于存在已被证明有效且安全的其他抗抑郁药，目前5-HTP和色氨酸的临床实用性有限。
