An amphetamine-suspension pilot showed improvement in classroom symptom ratings at 30 minutes, but its math-performance measures did not significantly improve at that time. The answer to how quickly treatment worked depended on the endpoint.
Childress and colleagues enrolled 18 children aged 6–12 years with ADHD. After open-label dose optimization and classroom practice, participants completed active-drug and placebo laboratory-classroom days in randomized sequence under double-blind conditions. Open-label treatment separated the two test days.
The primary endpoint was change from predose in the combined classroom-behavior rating at 30 minutes. Math problems attempted and correctly completed were separate performance outcomes. These measures address related aspects of classroom functioning, but they are not interchangeable.
At 30 minutes, the behavior-rating comparison significantly favored the extended-release amphetamine suspension. The math comparisons did not reach significance. At three hours, both the behavior rating and the numbers of math problems attempted and correct significantly favored active treatment.
Consequently, a statement that the medicine improved all classroom outcomes within 30 minutes would overstate the evidence. Conversely, the nonsignificant early math result does not establish that no child experienced a benefit, or that the true group effect was exactly zero. It indicates that this pilot did not establish that particular advantage at that assessment.
The sample was very small and excluded children with a known lack of response to amphetamine medication. This enrichment can influence estimated efficacy and tolerability. The authors discussed limited statistical power and the practical challenges of giving math assessments very early in the morning.
The study was industry sponsored, and the crossover involved brief test-day comparisons rather than long-term academic follow-up. Its results do not establish improved grades, an exact onset for each child or a drug-detection threshold. For evidence review, the useful distinction is between a significant early observer rating and an early objective performance comparison that remained nonsignificant.
Read our analysis of assessment windows in the larger suspension classroom study.
Early-Onset Efficacy and Safety Pilot Study of Amphetamine Extended-Release Oral Suspension in the Treatment of Children with Attention-Deficit/Hyperactivity Disorder. doi:10.1089/cap.2018.0078.