Christensen was born in Vancouver, British Columbia, to Alie, an American speechwriter, and David Christensen, a Canadian computer programmer and communications executive. His father is of Danish descent, and his mother has Swedish and Italian ancestry. Christensen is one of four children, with three actor siblings: older brother Tove, older sister Hejsa, and younger sister Kaylen. Christensen was an athlete in high school, playing hockey competitively and tennis on a provincial level.

Christensen made his acting debut in September 1993, when, at the age of 12, he played a supporting role on the German-Canadian television series Macht Der Leidenschaft/Family Passions. The following year, he had a minor role in John Carpenter's In the Mouth of Madness. From 1995 through 1999, he appeared in several films and television series, including Harrison Bergeron, Forever Knight, Goosebumps, The Virgin Suicides, and Are You Afraid of the Dark?  He acquired wider notice while starring in Fox Family Channel's television series Higher Ground in 2000, portraying a teen who was sexually molested by his stepmother, and then turned to drugs in his despair.  Christensen's critically acclaimed portrayal of a misunderstood teenager in Life as a House (2001) earned him Golden Globe and SAG Award nominations, as well as the National Board of Review's award for Breakthrough Performance of the Year. However, the performance did not receive widespread public notice. In 2002, Christensen made his London theatre debut with Jake Gyllenhaal and Anna Paquin in This Is Our Youth.  He went on to receive good reviews for 2003's Shattered Glass, which tells the true story of journalist Stephen Glass, who was discovered to be fabricating stories as a writer for The New Republic and other publications. Peter Travers of Rolling Stone wrote, "Hayden Christensen is sensational as Glass, finding the wonder boy and the weasel in a disturbed kid flying high on a fame he hasn't earned." In 2005, Christensen made his Broadway debut when he appeared briefly in a 10-minute play.  In 2005, he took part in the fifth annual "24 Hour Plays" benefit, which raises cash for nonprofit groups in the Big Apple.

Using a quote from the above article, answer the following question: what award did he win?
the National Board of Review's award for Breakthrough Performance of the Year.