Why are people who watch Tourette's videos on TikTok now experiencing symptoms?

The vast majority of people who suffer from Tourette’s syndrome – a condition of the nervous system that causes involuntary tics and twitches – only experience mild symptoms: coughing, blinking, small movements of the head or limbs. But there has long been public fascination about its more extreme manifestations: the shouting of random words, swearing and violent movements. Such cases tend to receive disproportionate and sensationalist media coverage, and in the modern era, that has converted to big numbers on social media.

In the past few months, there has been a huge increase in the number of TikTok videos with the hashtag #tourettes, and collectively, they have received more than three billion views since January. What few people could have predicted, however, is how this phenomenon has given rise to a new illness, where young people present identical symptoms to those of popular online creators.

One of those, Jan Zimmermann, a German YouTuber, has more than two million subscribers and ranks in the top 100 German YouTube channels.

Dr Kirsten Muller-Vahl, professor of psychiatry at the Hanover Medical School and a Tourette’s specialist, discovered earlier this year that significant numbers of young adults and teenagers were presenting the same symptoms as Zimmermann’s. “All these patients confirmed that they had watched [the channel],” she says. “Their symptoms started only after watching it, and no one in the Tourette’s community had ever seen [these particular symptoms] before.”

To Muller-Vahl, the relationship was clear. “This is a kind of mass sociogenic illness,” she says. “These are not voluntary movements or behaviour. It is a disease. But the name of this disease is not Tourette’s.”

Doctors in the US, UK, Canada and Germany reported similar findings. According to a recent article in The Wall Street Journal, four American clinics dealing with movement disorders have seen many more teenagers – particularly girls – being referred with tics; one, the Cincinnati Children’s Hospital Medical Centre, reported a ten-fold increase.

A paper published in the British Medical Journal in March this year was the first to make a tentative link to social media; while it noted that the increase in the number of people with tics could be linked to the many stress-related symptoms seen during the Covid-19 pandemic, it concluded: “The role of social media needs further exploration, particularly the potential for ‘contagion’.”

Muller-Vahl terms it MSMI, or “mass social media-induced illness”, and it appears to result from the rise in anxiety and depression owing to the pandemic, coupled with the growing popularity of influencers presenting Tourette-like symptoms.

Sociogenic illness is not new. Dr Erica Weir, a clinical epidemiologist, describes pre-20th century outbreaks of “convulsions, contractures, tremors, paralysis and laughing” ascribed to “long-standing religious, academic or workplace discipline”. More recently, in 2011, 20 teenage girls at a school in Le Roy, New York, suddenly developed tics which were later diagnosed as a sociogenic illness. The tics improved after the school term had ended.

But a paper published in the journal Movement Disorders in July says that while previous examples of sociogenic illness have been geographically isolated, the internet’s global reach changes everything. The numbers with MSMI are small, but its rise is fascinating: truly an illness for the modern age.

There’s a further complication. The MSMI tics being reported by clinics are, in fact, atypical of Tourette’s syndrome. This has led to increased scrutiny of some of the social media stars using the #tourettes hashtag, and debate over whether their symptoms are consistent with Tourette’s, or some other functional disorder, or are simply being concocted for the cameras.

A study of TikTok videos undertaken by the Rush University Medical Centre in Chicago found that while 93 per cent of the subjects made involuntary obscene gestures or used obscene language, the typical percentage of those with Tourette’s who do the same thing is between 8 and 14 per cent. “It's difficult to say what all these influencers are really suffering from,” says Muller-Vahl. “Some suffer from Tourette’s. The majority I think also suffer from functional symptoms [that are not Tourette’s].”

Young people who choose to share their Tourette's-like symptoms on social media may find an audience keen to offer attention and support, but as noted by Dr Isobel Heyman in the British Medical Journal, “this may be inadvertently reinforcing and maintaining symptoms”.

Muller-Vahl believes there is also a bandwagon effect at work. “If you ask me if I believe that some of these people are malingering, or pretending to have these symptoms, I would say yes,” she says. “There are some [influencers] who imitate this kind of behaviour because they feel people like it.”

There is no suggestion that the young people now being referred to clinics with tics are pretending to be unwell. What Muller-Vahl and others are urging is that their illness be treated properly and not misdiagnosed; doctors interviewed by The Wall Street Journal stressed that these tics can be addressed with therapy.

Meanwhile, the growing mischaracterisation of Tourette’s across social media is proving unhelpful to those truly suffering from the disease. According to Muller-Vahl, many are becoming reluctant to admit their diagnosis at all. “Patients tell me that people always ask them what kind of swear words they shout, whether they smash eggs [while cooking] and other bizarre behaviours not related to Tourette's.” Then, when they respond truthfully, they’re invariably told that their Tourette’s isn’t real.

Tourette’s is, of course, real, but so is sociogenic illness. So is viral popularity on social media, and so is the pandemic. Together, they have created an unfortunate perfect storm.