Closed-loop tTIS Targeted of the Nac as an Intervention for MUD Patients

Visual Analog Scale, range0-100 point. the higher the score, the more one wants drugs.

Drug-related obsessive thoughts and compulsive behaviours will be assessed using the Obsessive-Compulsive Drug Use Scale (OCDUS). The scale consists of 14 items rated from 0 to 4, producing a total score ranging from 0 to 56. Higher scores indicate more severe drug-related obsessive thoughts, craving, and impaired control over drug use.

Impulsive tendencies will be assessed using the Impulsive System subscale of the Dual-Mode of Self-Control Scale (DMSC-S). The subscale contains 12 items rated from 1 to 5, producing a total score ranging from 12 to 60. Higher scores indicate stronger impulsive-system tendencies, including greater impulsivity, distractibility, and preference for immediate gratification.

Self-control will be assessed using the Control System subscale of the Dual-Mode of Self-Control Scale (DMSC-S). The subscale contains 9 items rated from 1 to 5, producing a total score ranging from 9 to 45. Higher scores indicate stronger self-control, including better problem-solving and future-oriented planning.

Response inhibition will be assessed using the Stop-Signal Task. The primary behavioural parameter will be the reaction time and accuracy, measured in milliseconds. A longer stop-signal reaction time indicates poorer inhibitory control, whereas a shorter stop-signal reaction time indicates better inhibitory control.

The mean amplitude of the stop-related event-related potential and functional connection will be measured in microvolts over frontocentral electrodes within the prespecified post-stimulus time window.

delay discounting task,Delay of gratification will be assessed using a computerised delay-discounting task in which participants choose between smaller immediate rewards and larger delayed rewards. The discounting-rate parameter, k, will be estimated from participants' choices. A higher k value indicates steeper delay discounting, a stronger preference for immediate rewards, and a lower ability to delay gratification.

Reward learning will be assessed using a computerised reinforcement-learning task. A computational reinforcement-learning model will be fitted to participants' trial-by-trial choices. The learning-rate parameter, alpha, ranges from 0 to 1 and represents the extent to which recent feedback is used to update expected values. Higher values indicate greater updating in response to recent feedback.

Sensitivity to punishment will be assessed using the Sensitivity to Punishment subscale of the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ). The subscale contains 24 dichotomous items scored 0 or 1, producing a score ranging from 0 to 24. Higher scores indicate greater sensitivity to punishment.

Sensitivity to anticipated punishment will be assessed using the 7-item Behavioural Inhibition System subscale of the Behavioural Inhibition System/Behavioural Activation System Scales. Each item is rated from 1 to 4, producing a score ranging from 7 to 28. Higher scores indicate greater behavioural inhibition and sensitivity to anticipated punishment.

Depressive symptom severity will be assessed using the Beck Depression Inventory-II (BDI-II). The inventory consists of 21 items rated from 0 to 3, producing a total score ranging from 0 to 63. Higher scores indicate more severe depressive symptoms.

Attentional interference from methamphetamine-related cues will be assessed using a computerised drug-cue Flanker task. The drug-cue attentional interference effect will be calculated as the difference in mean reaction time between trials containing methamphetamine-related cues and trials containing neutral cues, measured in milliseconds. A larger positive value indicates greater attentional interference from methamphetamine-related cues.

Theta-band power will be quantified within the prespecified frequency range, electrode region, and post-stimulus time window. The cue-related theta effect will be calculated as the difference between methamphetamine-related and neutral cue conditions. A larger value indicates a stronger theta-band response to methamphetamine-related cues.

Task-related electroencephalography will be recorded during the drug-cue Flanker task and the reward learning task. The mean amplitude of the P3 event-related potential will be measured in microvolts within the prespecified electrode region and post-stimulus time window. A larger positive difference indicates greater neural reactivity to methamphetamine-related cues.