At least 20% of American children will suffer from a mental disorder that will impede their performance and achievement abilities sometime during their young lifetime, according to a new national study. Researchers have found this prevalence of poor mental health among adolescents to be evidence of the fact that most mental health issues in adulthood begin during adolescence. Many regional studies have shown that about one in every four to five children in the U.S. is currently struggling with a mental health disorder. In their latest investigation, researchers from the National Institute of Mental Health sought to discover whether this statistic held true across the entire nation\u2019s population of young people. Lead researcher Kathleen Merikangas and her colleagues surveyed a total of 10,123 U.S. adolescents between the ages of 13 to 18 years using the National Comorbidity Survey\u2014Adolescent Supplement (NCS-A) as well as the World Health Organization Composite International Diagnostic Interview. These assessments are designed to help recognize the presence of chronic mental disorders, level of severity of these disorders, comorbidity of disorders, as well as associated sociodemographic characteristics. The researchers compared the teens\u2019 responses to the answers of their parents\/guardians in a follow-up questionnaire and identified the presence of lifetime mental disorders in the adolescents by assessing data based on the American Psychiatric Association\u2019s Diagnostic and Statistical Manual (DSM-IV). The study was the first to investigate nationwide prevalence of childhood mental disorders. Overall, the researchers found that nearly half of adolescents met the criteria for at least one mental disorder during their lifetimes, and around 40% of adolescents considered as having one type of mental disorder also qualified for diagnosis of a different type of chronic mental disorder. Anxiety disorders were the most widespread mental health condition among the adolescents at 31.9%, followed by behavioral disorders at 19.1%, mood disorders at 14.3%, and substance abuse disorders at 11.4%. The average age for anxiety onset was 6 years; average onset for behavioral onset was 11 years; onset for mood disorders was 13 years; and onset for substance abuse disorders was 15 years. Because the researchers found several mental disorders were prevalent among the participants at a young age, the findings suggest that common mental health conditions recognized during adulthood actually first begin during childhood. Researchers suggest that more early intervention and treatment resources are needed to meet the mental health needs of U.S. adolescents in order to prevent future chronic mental health conditions during adulthood. Of those considered to have a lifetime mental disorder, 22.2% were suffering from symptoms severe enough to significantly impair or distress their normal lifestyles. Among those classified as having severe mental health diagnoses, 11.2% had mood disorders (including depression or bipolar disorder), 9.6% had behavioral disorders (such as conduct disorder or attention deficit hyperactivity disorder), and 8.3% had at least one anxiety disorder. Those with a mood disorder were the most likely to have a comorbid mental disorder compared to other adolescents. In comparison to their parents, adolescents tended to have strong associations between their mental health and their parents\u2019 characteristics. For example, teens with divorced parents were more likely than teens with married or cohabiting parents to have a mental disorder, particularly anxiety disorders, behavioral disorders, or substance abuse disorders. Adolescents of parents with less education were at a higher risk for any of the mental disorders compared to adolescents of parents with higher education. Moreover, the adolescents measured were more likely to have a mental disorder than a physical disorder, including diabetes or asthma. However, more research will be needed to determine the related causes between sociodemographic characteristics and development of childhood mental disorders, as well as other variables that may influence these outcomes, such as biological factors or genetics. The researchers recommend greater prevention and intervention strategies to more effectively reach American youth and circumvent prolonged conditions. Next, researchers say more investigation is needed to identify which mental disorders are more likely to continue into adulthood than other childhood disorders, as well as their variable risk factors. The researchers\u2019 study was published in the October issue of the Journal of the American Academy of Child & Adolescent Psychiatry.