What you need to know about your mental health Mental health is a major challenge facing teens today. According to the National Alliance on Mental Illness (NAMI), 50 percent of mental health conditions begin by age 14. This means many young people are struggling with the symptoms of mental health disorders prior to or during high school. Young people recognize the problems they are facing. A 2018 survey by the Pew Research Center revealed that 70 percent of teens surveyed believed that anxiety and depression are “major” challenges facing their peers.