In 2006, Doughty played with Team Ontario at the World U-17 Hockey Challenge, finishing fifth, then won a gold medal with the national under-18 team at the Ivan Hlinka Memorial Tournament. He participated the 2007 IIHF World U18 Championships, scoring five points in six games for the fourth place Canadians, and while he was considered for the Canadian junior team for the 2007 World Junior Ice Hockey Championships, he did not make the cut. Doughty was named to participate in the 2007 Super Series, an eight-game tournament against the Russian juniors meant to commemorate the 35th anniversary of the 1972 Summit Series. He played in all eight games, recording two assists, as Canada finished the series unbeaten with seven wins and a tie. He then earned a spot on the roster for the 2008 World Junior Ice Hockey Championships. Doughty was named a tournament all-star, and given the Directorate Award for Best Defenceman after helping lead the Canadians to their fourth consecutive gold medal at the tournament.