Browse every published article, from the latest research to earlier analysis. Use the page numbers below to explore the complete archive.
A brain-stimulation study reported a significant GABA-related reduction within the active-treatment group, but the active-versus-sham difference in change was not significant. The study illustrates why a significant result in one group and a nonsignificant result in another cannot substitute for a direct comparison. The intervention and the chemical measurement Su and colleagues randomized 50 methamphetamine-dependent…
A randomized Tai Chi study in women with methamphetamine dependence found a working-memory pattern consistent with relative maintenance while the comparison group worsened. That is different from showing that every executive function improved or that Tai Chi was superior on every test. The comparator was another exercise program The trial assigned 76 women in rehabilitation…
MRI volume changes during methamphetamine rehabilitation were associated with usual treatment and additional working-memory training. The scans did not establish growth of new neurons or prove that a larger region necessarily represented better function. The longitudinal comparison Brooks and colleagues recruited 66 men: 41 methamphetamine patients and 25 healthy controls. Within the patient cohort, 17…
Working-memory updating training improved performance on a trained task and a similar untrained task in abstinent methamphetamine inpatients. It did not demonstrate broader benefits for inhibition or task switching. Learning a task is not the same as improving executive function generally. Training was compared with an active control Zhao and colleagues studied 32 male inpatients…
A controlled trial detected no correlation between dexamphetamine plasma concentrations and the cognitive outcomes it measured. That result limits a simple concentration-to-performance interpretation within this experiment; it does not prove that concentration is irrelevant at every dose or in every population. Known dose, defined sampling times Pfoser-Poschacher and colleagues randomized 60 healthy men to a…
A four-week cognitive-training app trial reported improvements in selected memory and decision-task outcomes without a significant advantage in drug-related attention bias. The intervention did not demonstrate improvement in every domain it was designed to address. What was randomized Zhu and colleagues assigned 40 men with methamphetamine use disorder to computerized cognitive addiction therapy plus usual…
Lisdexamfetamine reduced reported methamphetamine-use days across a 12-week treatment period, but the trial’s primary endpoint at week 13 was not statistically significant. The study provides a treatment signal with important qualifications, rather than an unqualified positive result. A randomized outpatient treatment trial Ezard and colleagues randomized 164 adults with methamphetamine dependence at six Australian clinics…
A randomized trial found changes in brain activation and connectivity after active stimulation, but no significant advantage over sham stimulation in self-reported methamphetamine craving. The imaging findings should not be presented as proof of a clinical craving benefit. The intervention was brain stimulation Ekhtiari and colleagues randomized 60 people with methamphetamine use disorder to active…
An EEG component differed in methamphetamine-dependent participants without psychosis history, while reaction times and error rates showed no significant group differences. The finding does not establish a diagnostic EEG test for methamphetamine-associated psychosis. Who contributed to the analysis? Huang and colleagues recruited 31 healthy controls, 14 methamphetamine-dependent participants without psychosis history and 24 with a…
Eye tracking and reaction-time testing both indicated attention toward methamphetamine-related pictures in a small study of men with a history of use. These measurements captured allocation of attention to cues; they were not tests for identifying methamphetamine in the body. Direct and indirect attention measures Mirtorabi and colleagues compared 30 men who used methamphetamine with…
People with methamphetamine use disorder showed differences in recognizing happy faces, interpersonal trust and punishment choices in a clinical study. The study did not demonstrate a general loss of empathy, and its laboratory findings cannot establish that a particular person is violent or untrustworthy. A multidimensional human comparison Mahlberg and colleagues recruited 52 participants with…
A six-month study linked baseline cognitive performance with later methamphetamine-negative urine results, but its outcome also incorporated missed appointments: missing urine samples were counted as positive. That analytical rule matters when interpreting the paper as evidence about frequency of use. The prospective study Karabulut assessed 98 adults with methamphetamine use disorder using card sorting, Stroop…
Participants with methamphetamine use disorder explored uncertain options less and learned more slowly than controls in a decision task. Increasing bodily anxiety through breathing resistance did not significantly explain those group differences. The experiment therefore did not support a simple account in which induced anxiety caused the observed decision pattern. Learning about unfamiliar options Goldman…
Recently abstinent methamphetamine-dependent adults showed altered brain responses to gentle touch without significantly different ratings of how pleasant it felt. Lower activation should therefore not be described as proof that the participants could not experience pleasure. A controlled stimulus, an observational group comparison May and colleagues compared 25 recently abstinent methamphetamine-dependent adults with 17 comparison…
A brain signal during risky choices was associated with later relapse in an early-abstinent methamphetamine cohort. It was a promising research association, not a validated test that can tell whether a particular person will resume use. What was measured before follow-up Gowin and colleagues scanned 68 methamphetamine-dependent adults enrolled in treatment during early abstinence. Participants…
Methamphetamine-dependent adults showed differences in adjusting after stop errors even though their average stop-signal reaction time did not significantly differ from controls. A single summary measure of inhibition can miss how people adapt to unexpected events. A stop task with changing expectations Harlé and colleagues studied 62 recently abstinent methamphetamine-dependent participants recruited from an inpatient…
Brain responses to methamphetamine-related cues changed over the course of a scanning task. An average activation map can therefore hide changes occurring within the session, but declining cue-related activation alone does not prove that craving or relapse risk has improved. The study examined dynamics within recovery Jafakesh and colleagues analyzed functional MRI data from 62…
Methamphetamine-dependent participants and controls earned similar rewards on a laboratory choice task, but computational models suggested different ways of learning and choosing. Equal final scores therefore did not establish that the underlying decision processes were identical. How the two-option task worked Harlé and colleagues compared 16 methamphetamine-dependent adults with 16 healthy controls. Participants repeatedly selected…
A white-matter measure correlated with Stroop interference among abstinent methamphetamine users even though the corrected imaging difference between users and controls was not statistically significant. Those two findings answer different questions and should not be merged into a claim of proven brain damage. The comparison and the measurements Salo and colleagues compared 37 currently abstinent…
Higher denial of drug problems was associated with poorer cognitive performance in a study of methamphetamine-dependent adults. That finding supports investigating insight; it does not establish that a particular person is lying, lacks capacity, or cannot understand consequences. What the researchers measured Dean and colleagues studied 58 adults who were not seeking treatment. Participants completed…
A randomized pilot found lower reported cocaine craving with lisdexamfetamine without a significant reduction in cocaine use in the randomized sample. Craving and a urine-based use endpoint should not be substituted for each other. The intervention and the analyte The trial assigned 43 cocaine-dependent participants to placebo or lisdexamfetamine, 70 mg, for 14 weeks. There…
Improving ADHD symptoms did not produce a demonstrated smoking-cessation advantage in a small lisdexamfetamine trial. Treating one clinical problem and changing a separate substance-use outcome are different propositions. A medication added to a quit attempt The pilot randomized 32 regular smokers with ADHD to lisdexamfetamine or placebo, with 17 and 15 participants in the respective…
A study associated FAAH gene variation with differences in self-reported arousal and fatigue after amphetamine. Those findings address subjective drug response, not a demonstrated genetic predictor of cognitive enhancement or impairment. A placebo-controlled genetic association study The researchers examined healthy young adults in a double-blind crossover design involving placebo and oral d-amphetamine at 10 and…
A trial comparing amphetamine-dextroamphetamine with modafinil did not establish non-inferiority on its primary sleepiness endpoint. That statistical result does not, by itself, prove that amphetamine-dextroamphetamine was inferior. A prespecified non-inferiority question The randomized, fully blinded trial included 44 adults with idiopathic hypersomnia or narcolepsy type 2. Over 12 weeks, medication was individually titrated up to…
A study found that subjective amphetamine response changed the statistical relationship between negative emotionality and reported alcohol use. The result was not evidence that an amphetamine challenge can reliably forecast an individual’s future drinking. Personality, use history and a laboratory response Allen and Gabbay assessed personality and alcohol or drug-use history in healthy young adults.…
A PET study found that variation in schizotypal personality traits was associated with amphetamine-evoked dopamine-related changes. The finding concerned a research sample screened for psychiatric illness; it was not a diagnostic test for schizophrenia. Traits and a pharmacological challenge Woodward and colleagues studied 63 healthy individuals using a self-report Schizotypal Personality Questionnaire and fluorine-18 fallypride…
Participants with more attention lapses liked a 20-mg d-amphetamine dose less than those with fewer lapses in one healthy-volunteer study. This finding runs against a simple assumption that worse attention necessarily predicts stronger subjective stimulant reward. How the groups were formed McCloskey, Palmer and de Wit divided 99 healthy volunteers into three equal groups based…
A study related sensation-seeking scores recorded during adolescence to drug responses in young adulthood. Higher sensation seekers showed larger effects on several outcomes, but the direction depended on whether the drug was a stimulant or a sedative. A trait measured before the laboratory experiment Kelly and colleagues recruited young adults aged 18–21 who had consistently…
An amphetamine-challenge PET study found a larger striatal dopamine-related response in adults with ADHD than in controls. Cognitive testing occurred separately without the drug, so the study should not be described as directly showing amphetamine-induced improvement or worsening of inhibition. Imaging and cognition used different sessions Cherkasova and colleagues studied 15 treatment-free men with ADHD…
A rat experiment found that amphetamine could increase running duration without improving running economy. In a warm environment, the lower tested dose prolonged running, while the higher dose did not, and both doses increased temperature at exhaustion. Several experiments addressed different questions Zaretsky and colleagues studied male Sprague-Dawley rats using treadmill protocols. Separate experiments examined…