When your teenagers tell you they're stressed, believe them. In a new survey from the American Psychological Association, more than half of U.S. students cite a moderate amount of stress during the past school year.  More than a quarter say they experienced "extreme stress."

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"Survey findings suggest that the patterns of unhealthy stress behaviors we see in adults may begin developing earlier in our lives," the APA stated. "Many American teens report experiencing stress at unhealthy levels, appear uncertain in their stress management techniques and experience symptoms of stress in numbers that mirror adults' experiences."

Stressors can range from friends and social media to a calendar loaded with academic and athletic demands.

"Kids are doing more than ever before," explained Dr. Steven Tobias, director of the Center for Child and Family Development in Morristown. "The more we demand of kids nowadays, and the more they demand of themselves sometimes, the more they're going to be stressed out by it."

The survey touched on a variety of stress "aftershocks" that were reported by teens, including anxiety and depression. Nearly one-quarter of teenagers have skipped a meal due to stress, according to the survey, and more than 25 percent reported changes in sleeping habits. Research has shown a link between stress and a weaker immune system, as well as heart disease.

Tobias noted stress "makes everything worse" and can "exacerbate any other weaknesses" one may be facing.

Nearly half of teens admitted they're either not doing enough to manage their stress or are unsure how to best address it.

"Kids need down time," said Tobias, noting that down time shouldn't include staring at a computer screen or television. "You need to hang out with your friends sometimes. You need to have hobbies, interests, non-academic things that you can do."