Temporary Chronological Displacement Deterioration

Temporary Chronological Displacement Deterioration, or TCDD for short, was the condition which gave sufferers short term memory loss after travelling in time.

After being touched by a Weeping Angel, and sent back from 2015 to 1511, Gabby Finch was told by the Fifth Doctor that she was suffering from this condition after she told him that she could not remember the specifics of their meeting at the Sistine Chapel. (AUDIO: Fallen Angels)