The constitution of Bavaria was amended on 4 November 1913, to include a clause specifying that if a regency for reasons of incapacity lasted for ten years with no expectation that the King would ever be able to reign, the Regent could proclaim the end of the regency and assume the crown himself.
The following day, Otto was deposed by his cousin, Prince Regent Ludwig, who then assumed the title Ludwig III. The parliament assented on 6 November, and Ludwig III took the constitutional oath on 8 November. Otto was permitted to retain his title and honours until his death in 1916.
Bavaria had, thus, two kings, from 1913-1916. Many Bavarians saw this as a curse and two years after Otto's death, monarchy in Bavaria came to an end. The Luitpold branch of the Wittelsbach family was not very much liked by the Bavarians. Manys saw Luitpold and his son Ludwig - Ludwig II's uncle and cousin - as the mastermind of Ludwig II's deposition and his death.
Otto became King but under the Regency of his uncle Prince Luitpold of Bavaria until 1912. Otto was removed from the throne in 1913 when Luitpold's son Ludwig became King.
Allan Raymond
I think that it was schizophrenia. I may be confused but I think that Otto never became King of Bavaria, because of his mental illness. Otto was declared insane before Ludwig became King and, therefore, had no claims to the Bavarian throne.