重度忧郁症仍然难以治疗，许多患者对主要基于 1980s 开发药物类别的药物没有反应，因此研究人员测试了二甲基色胺（DMT，ayahuasca 中的迷幻剂）作为起效更快的选项。在这项小型临床试验中，研究评估了单次静脉注射剂量的快速抗忧郁效果，并强调 DMT 约 30 分钟的急性精神活性时间窗，在受监督照护情境中相较于 psilocybin 约 2 小时的持续时间具有实务优势。

该研究纳入 34 名临床忧郁症成人，采用 2-stage 设计：先进行盲法的 DMT 对 placebo 阶段，接著在 2 周后进入所有受试者都在完全告知下接受 DMT 的阶段。在 2 周时点，先接受 DMT 的参与者在标准忧郁量表上的降幅大于最初接受 placebo 者。第二次给药阶段后，抗忧郁效益可持续至多 12 周，而暴露于 2 次 DMT 剂量与 1 次剂量者之间的分数差异已不再观察到。

在这组资料中，安全性讯号可管理；通报的不良反应如输注部位疼痛、恶心与焦虑，多为轻度到中度，但 34 的样本量限制了统计确定性与可推广性。主要注意事项包括：由于迷幻效应明显而可能发生去盲，以及参与者原本就偏好迷幻治疗所带来的预期偏差，这些都可能放大自我回报的改善。这些发现强化了医疗监督下迷幻剂可快速且可能持久产生抗忧郁效果的证据趋势，同时也凸显需要与既有治疗进行比较、且规模更大的试验。

Major depressive disorder remains difficult to treat, with many patients not responding to medicines largely rooted in drug classes developed in the 1980s, so researchers tested dimethyltryptamine (DMT), a psychedelic in ayahuasca, as a faster-acting option. In this small clinical trial, a single intravenous dose was evaluated for rapid antidepressant effects, with DMT’s acute psychoactive window of about 30 minutes highlighted as a practical advantage over psilocybin’s roughly 2-hour duration in supervised care settings.

The study enrolled 34 adults with clinical depression and used a 2-stage design: an initial blinded DMT-versus-placebo phase, followed 2 weeks later by a phase in which all participants received DMT with full disclosure. At the 2-week mark, participants who received DMT first showed larger reductions on standard depression scores than those initially given placebo. After the second dosing phase, antidepressant benefits persisted for up to 12 weeks, and score differences between people exposed to 2 DMT doses versus 1 dose were no longer observed.

Safety signals were manageable in this dataset, with reported adverse effects such as infusion-site pain, nausea, and anxiety mostly mild to moderate, but the sample size of 34 limits statistical certainty and generalizability. Key caveats include likely unblinding because psychedelic effects are obvious and potential expectancy bias from participants already favorable to psychedelic therapy, which can inflate self-reported improvement. The findings strengthen a trend of evidence for rapid and potentially durable antidepressant effects from medically supervised psychedelics, while underscoring the need for larger comparative trials against existing treatments.