The tics started when J. H. was only 12 years old. Over time her condition worsened until she was having whole-body fits and being rushed to hospital.

But her local hospital in Durham, England, was dismissive, suggesting she had anxiety, a mental health condition, and that she was probably spending too much time watching videos on TikTok. Her mother describes the experience as “belittling”.

J.H. had an autoimmune condition brought on by a bacterial infection with Streptococcus. The condition is a Paediatric Autoimmune-Neuropsychiatric disorder associated with Streptococcus (pandas). When the infection was identified and treated, her symptoms finally improved.

Ms J.H. is not alone in having a dysfunction in the brain that is mistaken for one in the mind. Evidence is accumulating that an array of infections can, in some cases, trigger conditions such as obsessive-compulsive disorder, tics, anxiety, depression, and even psychosis.