A 16-year-old German girl's undiagnosed depression and temporal lobe epilepsy spiral into psychiatric crisis when doctors and family misinterpret her hallucinations as demonic possession, setting the stage for a tragic exorcism that would become a landmark legal case. Annalise Michel experienced seizures and vivid hallucinations of grotesque faces and voices between 1968-1973, but multiple neurologists diagnosed temporal lobe epilepsy and depression rather than possession, finding nothing abnormal on EEG tests. Her family became fixated on finding a Jesuit priest for exorcism after The Exorcist's 1973 release, despite priests like Father Herman and Father Alt repeatedly advising psychiatric treatment instead. Anticonvulsant medications prescribed by doctors may have caused hallucinations as a rare side effect, yet Annalise never reported worsening symptoms to her physicians, creating a feedback loop of misdiagnosis and deteriorating mental health. Poor communication between specialists, Annalise's reluctance to disclose depression and hallucinations, and her parents' rigid Catholicism created multiple institutional and familial failures that prevented proper psychiatric intervention.