About 11.2 percent or 499,000 of those aged between 12 and 18 suffered from depression at least once last year, according to the data submitted to Rep. Ahn Hong-joon of the ruling Saenuri Party by the Korea Centers for Disease Control and Prevention.
The figure compares with 10.5 percent in 2012, 10.8 percent in 2011, 10.4 percent in 2010 and 8.5 percent in 2009.
By gender, the rate of females who suffered from depression stood at 16 percent in 2013, more than twice as much as males (6.7 percent), the data said.
Rep. Ahn called for the introduction of a methodical management system to help improve the mental health of youth and strengthening of the role of health counselors at schools.