The growing scientific divide between ADHD research and treatments

As ADHD diagnoses continue to hit record highs across the US, many leading researchers are seeing a disconnect between scientists’ evolving knowledge of the condition and the way it’s being treated, per a New York Times Magazine report from child development expert Paul Tough.

Let’s break it down

In 1999, the first large-scale scientific study of how the stimulant Ritalin affects kids with ADHD published its initial results. This study, known as “MTA,” revealed strong evidence that children aged 7-9 with ADHD who took Ritalin every day had significantly fewer symptoms compared to a control group.

• MTA’s initial results gave many US clinics and doctors’ offices the green light to prescribe Ritalin—and later Adderall—to children across the US in the years following the study’s initial publication.

However…As scientists continued to follow the ~600 children in MTA, they realized newer data was telling a different story about Ritalin’s effectiveness. While children taking the stimulant did show improved behavior compared to other groups after 14 months of treatment, that advantage faded completely by 36 months.

Despite the newer data, stimulants remain the preferred ADHD treatment for most doctors. And the market for those stimulants has expanded rapidly in recent years in step with the growth of the condition.

• The percentage of US children diagnosed with ADHD has risen from 5.6% in 1999 to a record-high 11.4% last year.
• Meanwhile, US prescriptions for stimulants to treat ADHD increased by 58% from 2012-2022.

Bottom line: These millions of stimulant prescriptions rest on certain assumptions, including that ADHD has a largely biological basis and is diagnosed on a categorical model (either you have it, or you don’t). But many experts are beginning to question those assumptions, especially after the latest MTA study—published last October—found most subjects’ ADHD symptoms had fluctuated substantially over the years, mostly due to environmental factors.