Fugue state

From Tardis Wiki, the free Doctor Who reference

A fugue state was, according to the Tenth Doctor, "where the mind just runs away because it can't bear to look back."

Jackson Lake suffered from such a state when he lost his wife and son. While entering a fugue state, he saw an infostamp containing information on the Doctor, and began to think he was him. (TV: The Next Doctor)

Fugue state