In 2011, a Dutch psychiatric clinic was presented with one of the most terrifying mental disorders when a 52-year-old woman arrived for treatment.
The woman suffered from prosopometamorphopsia, a mental disorder that significantly warps the way one sees faces.
This woman's case, in particular, made the faces of others resemble those of dragons, Science Alert reports.
In The Lancet, researchers wrote,
Prior to her treatment, the hallucinations occurred too often for her to keep a job.
She underwent an MRI, an electroencephalogram (EEG), a blood test and several brain exams, but no abnormalities were found.
Doctors tried numerous treatments without success before finally curbing the hallucinations with Rivastigmine, an anti-dementia medication.
The medication reportedly targets acetylcholine, a neurotransmitter associated with learning and memory.
Rivastigmine is proven to allow sufferers of early-onset Alzheimer's disease recognize faces.
Currently, the woman has a steady job, and her hallucinations have lessened immensely.
It isn't clear what causes prosopometamorphopsia, but according to Science Alert, it can emerge after a stroke, a tumor or an experience with hallucinogenic drugs.
Hallucinations as specific as those suffered by this woman, however, are extremely rare.