The spread of the contagion tends to be a function of how connected the victims are to each other. So students at a small town high school, or workers on a factory floor, or even nuns in a convent.

这种"传染"的传播程度往往取决于受害者之间的关联性。比如小镇高中的学生、工厂工人，甚至修道院的修女。

In the Middle Ages, there were several cases reported in Europe in convents, including one extended case in France where a nun supposedly began meowing uncontrollably, only to have that symptom spread to the rest of the nuns in the convent.

中世纪欧洲就记录过数起修道院群体癔症，其中法国一起持续事件中，一名修女突然无法控制地学猫叫，随后症状传染了整个修道院。

And then, of course, there's the witches of Salem, right? Perhaps the archetypical women being hysterical. Many now believe that that was a mass psychogenic illness.

还有著名的塞勒姆女巫审判事件——如今许多人认为那正是一场群体性心因疾病，堪称"女性歇斯底里"的典型案例。

Why does it happen? There's usually some sort of underlying stress or trauma affecting the people involved.

为何会出现这种现象？通常与当事人承受的压力或创伤有关。

Like, for example, in the fall of 2001, when a mystery rash broke out in grade schools around the country, at least dozens and dozens of schools, hundreds of students affected.

例如2001年秋天，全美数十所小学爆发神秘皮疹，数百名学生受影响。

The rash would pass from student to student during the day in the school but then often disappear when the kid went home at night. And then it would reappear the next day and begin spreading all over again.

皮疹白天在校内传播，晚上学生回家后却常会消退，次日返校又再度爆发。

Tests showed no bacteria, no virus, no toxic exposure that would explain it. Turns out what may have been happening is that it was fear of toxic exposure that caused the contagion.

检测未发现细菌、病毒或毒素。真相可能是：对有毒物质的恐惧引发了这场"传染"。

In fact, the mystery rash began on the very day that the news reported that a man in Florida had been diagnosed with anthrax, just weeks after they began appearing in envelopes after September 11th in people's mailboxes.

事实上，神秘皮疹爆发当日，新闻正报道佛罗里达州发现炭疽病例——就在9·11事件后带炭疽菌信封出现的几周内。

Many epidemiologists now believe that the post-9/11 rash was a mass psychogenic illness, a real physical expression of the collective anxiety those kids were feeling at the time.

许多流行病学家现在认为，这场后9·11皮疹是群体性心因疾病，是孩子们集体焦虑的躯体化表现。

It's actually why I don't even care for the phrase "mass psychogenic illness." It's more polite, perhaps, but it's "mass hysteria" that really gets the messiness of it.

这正是我不喜欢"群体性心因疾病"这个术语的原因——它更礼貌，但"群体癔症"才真正捕捉到其中的混乱本质。

It's not just medical. It's not just psychological. It's social. It's cultural. It's about all of us.

它不仅是医学或心理学问题，更是社会文化现象，关乎我们所有人。

And it's not just women. You may have heard of Havana Syndrome. That's the neurological medical mystery affecting foreign workers in the United States and in Canada. Many people believe that that is a mass psychogenic illness.

不仅限于女性。比如"哈瓦那综合征"——这个影响美加外交人员的神经医学谜团，就被许多人认为是群体心因性疾病。

And these things don't just happen anywhere. They tend to happen at the stress points in the culture. Or as one expert put it to me, they tend to happen in the fissures of society.

这类事件往往爆发于文化压力点。正如一位专家所言："它们总在社会裂缝中滋生"。

I want to play you some more tape. These are all taken from police body cams of police officers in the field. In each instance, the police officer has just come into contact with the street drug fentanyl.

请听这些警用执法记录仪片段——每位警官都声称刚接触了毒品芬太尼。

It's so weird, man. He said he's floating. His legs are tingling. Yeah, yeah, my toes are tingling. We have fentanyl! We have fentanyl! You're good, you're good. You're good. Keep breathing. Hey, stay with me, OK? It's warrant officer. Possible exposure to fentanyl. I’m getting my -- you got yours out? All right. Relax."

太诡异了，他说自己在飘""我脚趾发麻""是芬太尼！坚持住！""我是巡警，可能接触了芬太尼""快拿解毒剂"...

You may have seen or heard footage like this in the news. It pops up all the time. 

Local新闻最爱这种戏剧性画面。我们追踪到332起类似案例——警员因"接触芬太尼"出现昏厥、刺痛、心跳加速等症状。

But of those 332 cases that we were able to track the number of actual toxicology reports that showed fentanyl in those police officers' system at the time, as far as we can tell, one.

但在这332起案例中，有确切毒理学报告证明警员体内含芬太尼的——据我们核实——仅1例。

At a state prison in Alaska. And even that one hasn't been independently confirmed. In fact, the American Society of Medical Toxicology says it is near impossible to overdose on fentanyl in this way.

（那例还在阿拉斯加州监狱，且未获独立验证。）美国医学毒理学会明确指出：这种接触方式几乎不可能导致芬太尼过量。

And yet, it keeps happening. But it doesn't happen to doctors and nurses who handle fentanyl in hospital settings. It doesn't even really happen to fentanyl abusers who are obviously handling the drug all the time.

然而事件仍在发生。奇怪的是，医院接触芬太尼的医护从未出现类似症状，长期接触毒品的瘾君子也不例外。

It's only in this one specific preexisting social group: police officers, male police officers, incidentally.

唯独这个特定群体——顺便说一句，主要是男性警官——反复出现这种状况。