A recent state-conducted health survey revealed a significant drop in smoking and alcohol consumption among South Korean teenagers over the past 20 years, but other negative trends in mental health and dietary habits are emerging.

The Ministry of Education and Korea Disease Control and Prevention Agency revealed Friday that the “current smoking rate,” -- measuring students who smoked at least once in the past month -- dropped from 11.8 percent in 2005 to 3.6 percent this year. Similarly, the proportion of students who had drunk at least one glass of alcohol in the past 30 days declined from 27 percent to 9.7 percent during the same period.

Despite progress in reducing harmful habits, dietary and mental health indicators have worsened. Breakfast skipping has surged, with 42.4 percent of teenagers regularly skipping their morning meal, up from 27.1 percent in 2005. Fast food consumption has also more than doubled since 2009, with nearly 29 percent of teenagers eating fast food three or more times a week.

Mental health trends have worsened over the last decade. While stress and depression rates improved between 2005 and 2015, they have since deteriorated. This year, 42.3 percent of teens reported experiencing significant stress, and 27.7 percent felt depressed enough to disrupt daily life for two weeks or more in the past year.

The annual survey, which began in 2005, collected responses from 60,000 students across 800 middle and high schools this year to offer insights into the evolving health landscape of South Korean teenagers, especially smoking, drinking and nutrition.