An ADHD imaging experiment found medication-related changes in working-memory networks, but its mixed individualized medications prevented attributing every result specifically to amphetamine. The study controlled active treatment versus placebo, not amphetamine versus another stimulant.
Eighteen youths aged 11–17 with combined-subtype ADHD completed a Sternberg working-memory task during functional MRI in a randomized double-blind placebo-controlled design. Active sessions used each participant’s standard effective medication and dose. The regimens included methylphenidate and dextroamphetamine/amphetamine combinations. Network analyses examined encoding/maintenance and retrieval phases separately.
Of six identified frontoparietal components, three increased activation on medication. Connectivity analyses also indicated recruitment of additional regions and strengthening of selected connections. Several connectivity changes were associated with faster working-memory responses. Those findings concern the prescribed stimulant regimens as a group. Methylphenidate is not amphetamine, and pooling the treatments does not establish that both produced identical regional effects.
The sample was small and consisted of established clinical responders using individualized doses. That differs from a trial assigning one drug at a common dose to previously untreated participants. Functional connectivity is a statistical relationship between imaging signals, not direct proof that one region repaired or controlled another. Associations with response time also do not establish causal mediation. The study supports investigating how effective stimulant treatment changes network engagement, while leaving drug-specific mechanisms and generalization unresolved. It supplies no basis for identifying ingestion, estimating blood concentration or determining impairment in a particular event.
See a study that directly compared two defined amphetamine formulations.