A nationwide shortage of stimulant medications used to treat attention-deficit hyperactivity disorder (ADHD) may be rooted less in prescribing practices or federal production quotas than in global supply chain disruptions, according to an analysis published late last week in JAMA Health Forum. The study, led by researchers from Yale University, examined potential causes of the US stimulant shortage in 2022 and 2023, when many patients reported difficulty filling their prescriptions.