Despite concerns that mental illness is rapidly spreading, a new report in the New England Journal of Medicine has found that in children, rates of treatment are going up and rates of diagnosis are going down.

Surveys from government organizations like the C.D.C. or the National Survey of Children’s Health have suggested that childhood mental disorders have become more prevalent. But this new study, authored by Columbia University psychiatrist Dr. Mark Olfson and his colleagues, calls those findings into question. Chiefly, it says that government surveys relied on flawed assessments that don’t adequately account for varying degrees of impairment.

The scale asks, for instance, how much of a problem a child has with “Feeling unhappy or sad?” “Having fun?” “Getting along with other kids?” “Feeling nervous or afraid?” The scale had 13 items in all, and parents assigned each one a “0,” for no problem, up to “4,” for a “very big problem.” Children whose scores were 16 or higher qualified as severely impaired. The data was drawn from in-depth household surveys performed by the Agency for Healthcare Research and Quality.

Between 1996 and 2012, the percentage of children and teenagers in that severe category dropped to 10.7 percent from 12.8 percent. That is a 16 percent decrease, and it was entirely unexpected, said Dr. Mark Olfson, of Columbia University, the study’s lead author.

Olfson posits that despite our modern worries about technology, social media, and “helicopter parenting,” a greater percentage of adults are being more attentive to their children’s health needs. As a result, children with psychiatric problems are being treated earlier on in life. In that same time period (1996 to 2012), the rate of young people undergoing therapy for mental disorders went from 9% to 13%. And among the most severely impaired, that figure rose from 26% to 44%. In total, there are about 2 million more children being treated for mental health disorders.