Anxiety, not depression, is the leading mental health issue among American youths, and clinicians and research both suggest it is rising. The latest study was published in April in the Journal of Developmental and Behavioral Pediatrics. Based on data collected from the National Survey of Children’s Health for ages 6 to 17, researchers found a 20 percent increase in diagnoses of anxiety between 2007 and 2012. (The rate of depression over that same time period ticked up 0.2 percent.)

Philip Kendall, director of the Child and Adolescent Anxiety Disorders Clinic at Temple University and a practicing psychologist, was not surprised by the results and applauded the study for its “big picture” approach.

The data on anxiety among 18- and 19-year-olds is even starker. Since 1985, the Higher Education Research Institute at UCLA has been asking incoming college freshmen if they “felt overwhelmed” by all they had to do. The first year, 18 percent replied yes. By 2000, that climbed to 28 percent. By 2016, to nearly 41 percent.

The same pattern is clear when comparing modern-day teens to those of their grandparents’ or great-grandparents’ era. One of the oldest surveys in assessing personality traits and psychopathology is the Minnesota Multiphasic Personality Inventory, which dates to the Great Depression and remains in use today. When Jean Twenge, a professor of psychology at San Diego State University, looked at the MMPI responses from more than 77,500 high school and college students over the decades, she found that five times as many students in 2007 “surpassed thresholds” in more than one mental health category than they did in 1938. Anxiety and depression were six times more common.

Those responding yes were asked to describe the level of both anxiety and depression in their children: 10.7 percent said their child’s depression was severe, and 15.2 percent who listed their child’s anxiety at that level.

Among the study’s other findings: Anxiety and depression were more commonly found among white and non-Hispanic children, and children with anxiety or depression were more likely than their peers to be obese. The researchers acknowledge that the survey method — parents reporting what they were told by their child’s doctor — likely skewed the results.

The causes of that anxiety also include classroom pressures, according to Grados. “Now we’re measuring everything,” he said. “School is putting so much pressure on them with the competitiveness … I’ve seen eighth graders admitted as inpatients, saying they have to choose a career!”

Yet even one of the latest study’s authors acknowledges that it can be difficult to tease out the truth about the rise in anxiety.

“If you look at past studies,” said John T. Walkup, chairman of the Department of Psychiatry at Lurie Children’s Hospital in Chicago, “you don’t know if the conditions themselves are increasing or clinicians are making the diagnosis more frequently due to advocacy or public health efforts.”

Nearly a third of all adolescents ages 13 to 18 will experience an anxiety disorder during their lifetime, according to the National Institutes of Health, with the incidence among girls (38.0 percent) far outpacing that among boys (26.1 percent).

Identifying anxiety in kids and getting them help is paramount, according to clinicians. “Anxiety can be an early stage of other conditions,” Grados said. “Bipolar, schizophrenia later in life can initially manifest as anxiety.”

For all these reasons, Kendall said, increased awareness is welcome.

“If you look at the history of child mental health problems,” he said, “we knew about delinquency at the beginning of the 20th century, autism was diagnosed in the 1940s, teenage depression in the mid-’80s. Anxiety is really coming late to the game.”