More South Koreans of all ages are suffering from depression, with the rise most significant among men in their 20s.

The National Health Insurance Service said Tuesday that a total of 599,200 patients visited hospitals for depression in 2015, a 16 percent surge from 516,600 in 2010.

The treatment cost for depression also jumped by 20.8 percent to 268.4 billion won ($233.8 million) from 222.2 billion won during the same period.

The largest percentage of the patients were women in their 50s, followed by women in their 60s and 70s. The organization said more significant, however, is the 40 percent increase in the number of male patients in their 20s. They said more men in their 20s are visiting hospitals for treatment as they suffer from various social stress such as in job seeking. The rise is also attributable to the eased negative perception about seeking psychological help, they said.