In 2014, dozens of teenage girls at a school in the Colombian town of El Carmen de Bolivar collapsed and had seizures. Within a day, the whole school was affected. Mass collapses such as this one are more common than you might think. One pupil faints and others quickly follow, in a fear-fueled domino effect. Typically, these crisis-moments are over in a day. But that hasn’t happened in Colombia. Six years on, girls at the school are still fainting. After making exhaustive investigations, local doctors have confidently diagnosed this as a case of “Mass Psychogenic Illness” — or, to put it in simpler language, mass hysteria. 

I am a neurologist and I have studied phenomena like this all over the world. I visited El Carmen de Bolivar to try to understand why the girls weren’t getting better. What I discovered shocked me. It turned out that the town had fallen prey to self-proclaimed “experts,” many from overseas, who had contacted the affected families after hearing about the case in the media. Many had no medical expertise, and each brought their own theories and diagnoses — often based on bad science. Through my research I learned that these supposed experts had convinced the girls that they had been poisoned. But the appropriate medical tests showed no such thing. 

The families in El Carmen de Bolivar were mirroring a wider trend in Colombia, where decades of institutional failings, drug-related corruption and violence have eroded trust in traditional authority figures, including even doctors. By contrast, they were open to the advice of strangers and welcomed their cures as a Godsend. It is an amplified version of the same phenomenon worldwide — where so many people now prefer to hear the views of opinionated amateurs or ill-informed do-gooders rather than those with genuine expertise. I encounter the result all the time in my work as a neurologist. At least once a week, I have a patient who dismisses my opinion in favor of something they have read on the internet or in a magazine. 

I am terrified of the Covid-19 pandemic. But I am also hoping something good can come of it — that it could make people trust scientists and other experts once again. It is telling that even President Trump has had to turn to experts as the pandemic has spread, after initially trying to play down the threat to Americans.  

Thanks to the internet, there has been a huge shift in how people learn about health issues. Not so long ago, advice on how to react to a pandemic would have come from a small range of mainstream media outlets. Now we can look things up for ourselves. If we face serious illness, being able to research symptoms and possible diagnoses and treatments online can offer a feeling of control. But there are so many sources of information it can be hard to pick out the good advice from the chaff — and so it can also exacerbate fear. 

Similarly, the Colombian families I talked to felt empowered with the advice they received from outsiders, but have ended up discounting the diagnosis of the real experts who could actually help the girls.

We live in a world overloaded with information, which also favors the loudest voices over the most knowledgeable. And with a little technical language, it is easier than ever to make fake or questionable science sound plausible. Commercial interests are withheld. One “doctor” or “scientist” might seem very like another to those not in the field. Most of the advisers who went to El Carmen de Bolivar called themselves doctors, but their doctorates were not in medicine. Many people may not know the difference.

It is easy to understand this loss of trust. In Colombia, the political instability of its recent past has given people good reason to doubt authority figures. The same problem can be seen elsewhere around the world. The British doctor Andrew Wakefield had a disastrous effect worldwide spreading dangerous misinformation about the supposed risk of the MMR vaccine causing autism — discrediting the profession in the process. America’s opioid drug crisis has cratered trust in pharmaceutical companies. And we have given up being surprised by populist politicians getting away with half-truths and lies. Who can blame people for being cynical?

It is also that much harder for real experts to maintain people’s confidence. Whether they specialize in viral outbreaks or other matters, they are held to an impossible standard. Inevitably, they will be wrong sometimes. But when they are, this is often used against them, to argue that they can’t be trusted. There is no such risk for the naysayer shouting from their social media soapbox, stirring a vortex of disinformation. Once they are proven wrong, they can simply move on to the next campaign. And the Covid-19 outbreak has proved fertile ground for such behavior, with many trying to dismiss the reaction as mass hysteria.

Some have raised concerns that the economic consequences will end up doing more harm than the virus itself, with businesses worldwide reeling under the impact. In my work I have seen many lives ruined by fear of the effects of disease rather than by the disease itself, so I am mindful of the risk. But the hard truth is that there is a legitimate reason to fear the Covid-19 pandemic.

To those who have tried to claim that the media have needlessly stoked anxiety with their coverage of the outbreak – in some cases even saying it has been a conspiracy to undermine Trump — I would say some anxiety is absolutely essential right now. I too have done an oversized grocery shop — because I can see the trends mean the situation could still get a lot worse. It is precisely because of people’s instinctive suspicions that they have taken so long to take the threat seriously. When news of an imminent lockdown in Northern Italy leaked out, some people fled the region before anybody could stop them. That was a selfish act that almost certainly heightened the risk both to themselves and others — and probably led to even more deaths. 

The same kind of sentiments are at work in the Colombian town of El Carmen de Bolivar. Faux experts have convinced the children that they have some mystery disease. But this hasn’t helped the girls — and the families have yet to recognize it.