Browse every published article, from the latest research to earlier analysis. Use the page numbers below to explore the complete archive.
A controlled experiment found improved information processing after d-amphetamine without a corresponding improvement in response inhibition. Handling a faster stream of information and stopping an initiated action were separable abilities. The experimental question Fillmore and colleagues studied 22 healthy adults without reported illicit-stimulant use or drug dependence. A randomized double-blind within-subject design compared placebo with…
A pilot experiment found no overall amphetamine benefit on spatial or digit-span memory, while psychosis-like experience ratings increased. A correlation between those changes did not prove a clinical psychotic disorder or its causal pathway. The experimental question Kassim and colleagues conducted two separate randomized double-blind placebo-controlled crossover pilots. Twenty participants received d-amphetamine 0.45 mg/kg in…
An oral-dose experiment found small changes in selected social ratings but no improvement in facial emotion recognition. Its results do not support a general claim that amphetamine makes people more socially perceptive. The experimental question Dolder and colleagues tested 24 healthy volunteers in a randomized double-blind placebo-controlled crossover experiment with equimolar d-amphetamine 40 mg and…
Repeated amphetamine exposure altered reward-related brain responses in healthy volunteers while rewarded reaction times remained unchanged. Sensitization therefore did not produce a uniform increase in every measured response. The experimental question O’Daly and colleagues used a randomized double-blind parallel-group design to examine acute amphetamine effects following a sensitizing regimen. Participants completed a rewarded gambling task…
A small experiment found that amphetamine increased choices requiring greater effort, especially when the chance of reward was lower. That did not mean the participants became more sensitive to the size of the possible reward. The experimental question Wardle and colleagues studied 17 healthy adults across placebo, 10-mg and 20-mg d-amphetamine sessions under counterbalanced double-blind…
An amphetamine study found related reward-evoked electrical responses in humans and mice, but the frequency-domain effects differed. Cross-species similarity was partial, not evidence that every neural measure responded identically. What the study measured Cavanagh and colleagues studied reward processing during a probabilistic learning task in 23 humans and 28 mice. Human conditions included placebo and…
Amphetamine increased willingness to keep working in a human effort task without changing the proposed parietal-alpha EEG marker. A measure that tracks task engagement need not track the drug-induced change in behavior. What the study measured Noback and colleagues tested 23 healthy adults in a double-blind placebo comparison using a progressive-ratio breakpoint task with EEG.…
Amphetamine altered EEG measures differently during easy and difficult trials. A single statement that the drug increased brain activity would miss the conditional nature of the findings. What the study measured Bhakta and colleagues studied 23 healthy adults in a randomized double-blind placebo-controlled within-subject experiment. Participants received 10 mg, 20 mg d-amphetamine and placebo across…
Humans and mice showed some similar attention benefits from amphetamine on related tasks, but the effects were not identical. Human reaction-time variability improved, while the mouse experiment did not detect that effect. What the study measured MacQueen and colleagues tested healthy adults on the five-choice continuous-performance task after placebo, 10 mg or 20 mg d-amphetamine.…
Amphetamine prevented the usual decline in attention across a continuous-performance task in healthy adults. The same experiment did not establish improvements in gambling decisions, card sorting or all measures of inhibition. What the study measured MacQueen and colleagues tested 69 healthy adults after placebo or 10 or 20 mg d-amphetamine. The Conners’ Continuous Performance Test…
A randomized obesity pilot did not demonstrate a treatment-specific improvement in executive-function ratings or stop-signal performance over time. A difference in weight outcome did not establish the proposed cognitive mechanism. What was measured Poulton and colleagues randomized 52 participants with body-mass indices of 25–60 to dexamphetamine titration or placebo. Participants completed a brief executive-function questionnaire…
A comparative study found bioequivalent exposure for a lisdexamfetamine solution and reference capsules under its prespecified criteria. Bioequivalence concerns selected pharmacokinetic summaries; it does not mean that every participant had an identical concentration at every sampling time. What was measured Rizea-Savu and colleagues studied single-dose comparative bioavailability in healthy volunteers. A validated liquid chromatography–tandem mass…
A small controlled trial reported attention-related benefits from lisdexamfetamine in selected children with persistent symptoms after traumatic brain injury. Improved attention testing did not establish that the medication repaired the underlying injury. What was measured Tramontana and colleagues enrolled 20 children aged 10–16 in a 12-week randomized double-blind placebo-controlled dose-titration crossover trial. Sixteen completed it.…
A controlled oral-dose experiment found later amphetamine exposure after lisdexamfetamine, without a significant reduction in peak drug-liking ratings compared with equimolar d-amphetamine. Delayed delivery did not automatically mean a lower peak subjective effect. What was measured Dolder and colleagues studied 24 healthy volunteers in a randomized double-blind placebo-controlled crossover experiment. Research doses were lisdexamfetamine 100…
A four-week adult ADHD trial recorded more insomnia adverse events with lisdexamfetamine, while the overall sleep-quality score did not differ significantly from placebo. These results can coexist because they measure different aspects of experience. What was measured Adler and colleagues analyzed sleep in a randomized double-blind forced-dose study of 420 adults assigned to placebo or…
A head-to-head ADHD study found comparable driving-simulator performance with lisdexamfetamine and extended-release methylphenidate. Because the trial lacked placebo, it could not quantify how much either improved performance over no active treatment. The research question Madaan and colleagues used a randomized double-blind crossover design in young adults with ADHD. Doses of each medication were optimized before…
Adding dexamphetamine did not make alcohol-impaired driving performance reliably safe in a controlled simulator study. A partial benefit on selected attention measures was not equivalent to reversing alcohol’s effects across driving tasks. The research question Simons and colleagues used a randomized crossover design with dexamphetamine 10 mg, alcohol 0.8 g/kg, their combination and placebo. Eighteen…
A placebo-controlled trial did not show a significant fatigue benefit from dexamphetamine in patients with stable primary brain tumors. A stimulant’s alerting reputation did not establish effectiveness for this clinically distinct form of fatigue. The research question Laigle-Donadey and colleagues conducted a double-blind multicenter trial of dexamphetamine sulfate, up to 30 mg daily, over three…
A two-year pediatric study did not observe potentially clinically significant deterioration in its key cognitive measures during lisdexamfetamine treatment. Without a control group, the same data could not establish that the medication caused the improvements observed in some tests. The research question Coghill and colleagues evaluated children and adolescents aged 6–17 receiving optimized lisdexamfetamine in…
An extended-release amphetamine suspension improved pediatric ADHD outcomes at assessments from one through 13 hours after dosing. Those observation points establish the tested window, not the precise minute effects began or ended. The research question Childress and colleagues evaluated children aged 6–12 in a dose-optimized randomized placebo-controlled study. A five-week open-label phase preceded a one-week…
A pediatric ADHD trial observed treatment effects through 12 hours after patch application, although patches were removed at nine hours. Patch removal and the end of a measured behavioral effect were therefore not the same event. Study design and population Cutler and colleagues studied a dextroamphetamine transdermal system in children and adolescents aged 6–17. An…
A structural MRI study found regional differences in both cortical thickness and gray-matter volume among people with methamphetamine use disorder. Those measures should not be treated as interchangeable evidence or a direct explanation of every cognitive deficit. Study design and population Zhou and colleagues compared 45 people with methamphetamine use disorder with 43 healthy controls…
Resting EEG patterns differed between people with methamphetamine use disorder and controls in a microstate study. These group differences did not validate a test for diagnosing intoxication or determining an individual’s cognitive impairment. Study design and population Chen and colleagues analyzed 55 patients with methamphetamine use disorder and 27 matched healthy controls. A 64-channel EEG…
A small study suggested larger oxygenation responses during higher-intensity exercise, but its highlighted regional and connectivity comparisons did not survive correction for multiple testing. It did not establish that harder exercise produced superior cognitive recovery. Study design and population Gao and colleagues randomized 20 abstinent methamphetamine-dependent men to moderate- or high-intensity cycling. Each session included…
Tai Chi outperformed running on selected attention outcomes in a 12-week trial of men with methamphetamine use disorder. It did not show a significant advantage for drug craving, so the cognitive finding should not be relabeled as reduced desire to use. Study design and population Zhang and colleagues randomly assigned 48 men to moderate-intensity Tai…
A methamphetamine rehabilitation trial reported exercise-related differences in selected circulating biomarkers, but not all markers changed differently between groups. Those blood measurements did not directly demonstrate repair of the blood–brain barrier. What the study tested Zhu and colleagues randomized methamphetamine-dependent men to 12 weeks of moderate aerobic exercise or conventional detoxification. The study measured neurofilament…
A 12-week exercise trial found reduced drug-cue attention bias in women with methamphetamine addiction. Differences in EEG components suggested changes in processing over time, but could not precisely locate the responsible cortical regions. What the study tested Zhao and colleagues randomized 63 women to dance, cycling or a control group maintaining regular activities with little…
Combining neurofeedback with swimming reduced image-induced craving in a small randomized study. The accompanying EEG changes did not establish that a particular frequency-band ratio caused the craving reduction. What the study tested Fadaei and colleagues allocated 32 methamphetamine-dependent patients to control, neurofeedback, swimming or combined neurofeedback/swimming groups. Resting EEG and visual-image-induced craving were assessed before…
A trial combining mindfulness and brain stimulation reported improvements in executive tasks and craving among young adults. Favorable combination results do not, by themselves, establish that the treatments interact synergistically. What the study tested Alizadehgoradel and colleagues randomized 80 early-abstinent methamphetamine users aged 18–21 to four groups: active transcranial direct current stimulation, mindfulness-based substance-abuse treatment,…
An eight-week smartphone intervention showed preliminary benefits for cue-induced craving and cognition. Its engagement data did not establish sustained abstinence or long-term clinical recovery. What the study tested Zhang and colleagues randomized 100 community participants with methamphetamine use disorder to a digital-therapeutics group or usual care. The application combined cognitive behavioral therapy, approach-bias modification, cognitive…