The New York City teacher who disappeared days before the start of the school year and was later rescued after jumping into New York Harbor says she had amnesia, the Daily News reports.

In her only remarks about the ordeal to date, 23-year-old Hannah Upp writes on her Facebook page that she was suffering from a condition called "dissociative fugue" (also known as "dissociative amnesia") when she was found in the waters off Staten Island — 19 days after she vanished.

"As is typical of a case of dissociative fugue, I was not aware of my own identity and I emerged from the episode with essentially no memory of what happened during the time I was missing," the Spanish teacher wrote in a message on the social networking site.

The disorder Upp describes causes sufferers to forget their pasts and abruptly run away from home and is typically triggered by trauma or acute stress.

The sudden disappearance of the Oregon native — a New York City teaching fellow at Thurgood Marshall Academy in Harlem — prompted a three-week-long search.

The mystery deepened with several confirmed sightings of Upp in New York while she was missing, culminating in her apparent suicidal leap into the river followed by her dramatic rescue by a Staten Island Ferry crew.

A doctor told the News that Upp's behavior wasn't typical of someone suffering from dissociative fugue.

Click here for more on this story from the New York Daily News.