After vacating his position as adjutant of the 4th Battalion, King's Own Scottish Borderers, another TA unit, in November 1923, Christison was assistant manager of the British Olympic team in Paris in 1924 which was followed by a further appointment as an adjutant, this time with his regiment. Still a captain, he attended the Staff College, Camberley from January 1927 to December 1928. His fellow students there included several who, like Christison, would eventually rise to high command, such as Oliver Leese, John Whiteley, Evelyn Barker, Robert Bridgeman, Eric Dorman-Smith, Ronald Penney and John Hawkesworth. His instructors included the likes of Richard O'Connor, Bernard Paget, Edwin Morris, Harold Franklyn, Henry Pownall, George Giffard and Bernard Montgomery. Shortly after graduating from Camberley he was appointed as a General Staff Officer Grade 3 (GSO3) at the War Office.