Cases of teen girls with involuntary tics are on the rise, and one common denominator is that the patients watch TikTok videos.

It seems the teens are developing their tics—similar to Tourette syndrome, though without a biological basis—after watching videos of TikTok users who say they have Tourette syndrome.

There's no sinister motive at play; on the one hand, TikTok provides a forum for those with Tourette syndrome or similar ailments to explain the issue and find support; on the other hand, those videos may have unintended consequences just now coming clear.