Teens Are Developing Tics. Doctors Say TikTok May Be A Factor.

Over the last year, there's been a sharp increase in teen girls seeking medical help for involuntary tics. Kayla Johnsen is one of them. She shares her story, and a neurologist explains why doctors think the social media app TikTok may be behind the medical phenomenon. Plus, WSJ's Julie Jargon traces the origin of the Tourette influencers whose videos may have sparked the surge. Learn more about your ad choices. Visit megaphone.fm/adchoices