The mystery of the sudden appearance of ‘schizophrenia’ in a 14-year-old boy, who endured 18 months of hospitalisations, specialist assessments and medications, has been found to have a feline cause.

Doctors believe cat-scratch disease — or infection with Bartonella henselae from a cat scratch — lay behind the boy’s sudden-onset psychotic symptoms, according to a case report by researchers at North Carolina State University in the US.

The family, who owned a number of pets including cats, first sought emergency care for the teenager in October 2015, when he suddenly had symptoms of feeling overwhelmed, confused, depressed and agitated.

“He said that he was an ‘evil, damned son of the devil’ and wanted to kill himself because he was afraid of his new-onset homicidal thoughts toward those he cared about,” the authors wrote in the Journal of Central Nervous Disease.