Rachel Busman, a clinical psychologist at the Child Mind Institute in New York City, said that it can be hard to think about depression in younger children because we picture childhood as a time of innocence and joy. But as many as 2 to 3 percent of children ages 6 to 12 can have serious depression, she said. And children with anxiety disorders, which are present in more than 7 percent of children aged 3 to 17, are also at risk for depression.