The mystery illness affecting 15 teens -- 14 girls and one boy -- from Le Roy High School in New York is reportedly also affecting a 36-year-old who lives in the area.
NBC News reported that Marge Fitzsimmons, who has lived her whole life in LeRoy, also started experiencing the Tourette-like symptoms in October -- around the same time a dozen teenage girls started experiencing the symptoms, which include uncontrollable tics and head shaking. Three more students -- including one boy -- came forward with symptoms late last month.
"When it first started I thought maybe I'm going crazy," Fitzsimmons told NBC News. "As an adult, I can't imagine these teenagers going through this and for anyone to think that they're faking it at all. Try living a day in their shoes."
The symptoms were so bad that she had to stop working.
"The motor tics wouldn't stop, and the vocal tics started, and I went to one of the bosses and said I have to go," Fitzsimmons told NBC News.
HLN reported that she was also diagnosed with conversion disorder, from stress and childhood trauma. The other teenagers at the high school have also been diagnosed by experts with conversion disorder, which is where a stress or psychological issue is manifesting in physical ways, with real physical symptoms.
Fitzsimmons told HLN that her doctor said it was like "everything you've ever suppressed in your whole life has just erupted like a volcano."
Previously, USA Today reported that Erin Brockovich -- the environmental activist who linked cancer cases with toxic drinking water in California, spurring a 2000 movie starring Julia Roberts -- has launched her own investigation into the cause of the illness.
Brockovich is getting involved upon finding out that there was a toxic chemical spill that occurred near the school 40 years ago, thereby contaminating the water and ground, USA Today reported.
However, the New York Department of Health has not found that there is any environmental or infectious cause of the mystery illness, with department spokesman Jeffrey Hammond telling ABC News that "the school is served by a public water system. ... An environmental exposure would affect many people."
Earlier this week, CNN reported that Le Roy Central School District is hiring an outside environmental testing company to test Le Roy High School and the surrounding community.
"Our community has suddenly found itself at the center of national attention due to the students who have been exhibiting neurological symptoms," school district superintendent Kim M. Cox said in a statement, CNN reported. "This has led to much speculation, conjecture and misinformation in the national media and consequently within our community."
Fitzsimmons told HLN that as a child, she hung out in a quarry near the chemical spill site.
"We used to do what teenagers do when you get a group of them together," she told HLN.