Over at Mental Floss, you can read about 10 reported incidents of Cotard's Syndrome. Synecdoche, New York's Caden Cotard was named after the bizarre condition. Matt Soniak describes it like this:
Cotard’s Delusion is a mental disorder where people suffer the nihilistic delusion that they are dead or no longer exist. First reported in the 1700s, the disorder is still a largely a mystery today. The underlying cause isn’t understood; it’s been linked to bipolar disorder, depression and/or schizophrenia depending on the patient’s age.
Here's #3 on the list:
3. In 2008, New York psychiatrists reported on a 53-year-old patient, Ms. Lee, who complained that she was dead and smelled like rotting flesh. She asked her family to take her to a morgue so that she could be with other dead people. They dialed 911 instead. Ms. Lee was admitted to the psychiatric unit, where she accused paramedics of trying to burn her house down. After a month or so of a drug regimen, she was released with great improvement in her symptoms. (Source)
That's not even the weirdest one.