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.
Jafakesh and colleagues analyzed functional MRI data from 62 men with methamphetamine use disorder during their first weeks in an abstinence-based treatment program. A combined cue-reactivity and Go/No-Go task required participants to view salient images and sometimes withhold a response. This was human research during recovery, not a controlled drug-dosing experiment.
The researchers divided the task into time windows and modeled cue reactivity, response inhibition and inhibition during drug-cue exposure separately. Selected regions, including temporal, amygdalar and hippocampal areas, showed declining drug-cue responses. Inhibitory contrasts showed time-dependent changes across a wider network. Drug-related inhibition involved changing activity in the parahippocampal regions and right precuneus.
A reduced response to repeated pictures may reflect habituation to those pictures. It does not by itself demonstrate a lasting reduction in the desire to use methamphetamine. The authors did not repeatedly measure craving throughout the task, so they could not directly track whether moment-to-moment craving changed alongside the neural signals. Nor did the study test whether these dynamic measures predicted later relapse.
There was no healthy control group, so the observed time patterns cannot be identified as unique to methamphetamine use disorder. All participants were treatment-seeking men. Salient pictures in one block could also influence responses in later blocks, and splitting data into windows reduces statistical power. Functional MRI measures a blood-oxygenation signal rather than drug concentration or individual driving ability. The findings justify studying timing more carefully; they do not yet validate a diagnostic or treatment-success test.
For a separate question, see cue-induced craving across abstinence groups.