In 2009, Susannah Cahalan was a healthy 24-year-old reporter for the New York Post, when she began to experience numbness, paranoia, sensitivity to light and erratic behavior. Grasping for an answer, Cahalan asked herself as it was happening, "Am I just bad at my job — is that why? Is the pressure of it getting to me? Is it a new relationship?"
But Cahalan only got worse — she began to experience seizures, hallucinations, increasingly psychotic behavior and even catatonia. Her symptoms frightened family members and baffled a series of doctors.