Identical device appearance and parameters, with minimal sensory stimulation and no vagal activation. The treatment schedule is identical to that of the active group.

Sleep quality will be measured by the Pittsburgh Sleep Quality Index (PSQI). The total score of PSQI ranges from 0 to 21, in which higher scores mean poorer sleep quality.

The GAD-7 is a self-report scale for assessing anxiety symptoms. It consists of seven items assessing: 1. nervousness or anxiety; 2. uncontrollable worry; 3. excessive worry; 4. difficulty relaxing; 5. restlessness; 6. irritability; and 7. a sense of imp

Risky decision-making performance will be assessed using the Balloon Analogue Risk Task (BART). Higher average pumps in the BART indicate greater risk-taking propensity. Electroencephalography (EEG) will be used to measure neural electrical signals, where increases in relevant electrophysiological indicators may reflect heightened individual sensitivity to negative feedback. Higher frequency of continued dice rolls indicates greater risk propensity. Neural activity features related to the task will be analyzed, with specific patterns associated with risk evaluation and reward processing.

A negative reinforcement learning paradigm was used to assess avoidance-reversal learning behaviour. Behavioural response bias and learning rate were used to characterise negative reinforcement behavioural traits and negative reinforcement learning ability. EEG was recorded simultaneously, and changes in relevant electrophysiological indicators may serve as electrophysiological markers of changes in negative reinforcement learning behaviour.

Alcohol craving will be measured by the alcohol craving Visual Analog Scale (VAS). The total score of VAS ranged from 0 to 10, in which higher scores mean a higher level of alcohol craving.

The AUDIT (the Alcohol Use Disorders Identification Test) consists of 10 items covering drinking frequency, alcohol consumption, alcohol dependence-related symptoms, and adverse consequences caused by alcohol use. Respondents complete the questionnaire based on their recent drinking behaviour, with each item scored according to different response levels. The total score ranges from 0 to 40. Higher scores indicate a higher risk of alcohol-related problems, and the scale can be used to identify hazardous drinking, harmful drinking, and potential risk of alcohol dependence.

The China version of the Connor-Davidson Resilience Scale (CD-RISC) consists of 25 items and includes three dimensions: tenacity (13 items), strength (8 items), and optimism (4 items). The scale uses a 5-point Likert scoring method, with scores from 0 to 4 representing "not true at all", "rarely true", "sometimes true", "often true", and "true nearly all the time", respectively. The total score ranges from 0 to 100, with higher scores indicating greater psychological resilience. The internal consistency coefficient of the Chinese version is 0.91.

Adverse Childhood Experiences (ACEs) includes 25 clinical items and 3 validity items. The scale uses a 5-point scoring system, ranging from "never true" to "very often true". Each subscale score ranges from 5 to 25 and is calculated by summing the scores of the items within that subscale. The total CTQ score is calculated by summing the subscale scores. Higher scores indicate more severe reported childhood maltreatment.

The FTND is a self-report scale used to assess the severity of nicotine dependence among smokers. The scale usually consists of six items. The total score ranges from 0 to 10, with higher scores indicating more severe nicotine dependence. It can be used to assess the level of smoking addiction and support the development of smoking cessation interventions.

Self-control ability will be measured using the Self-Control Scale (SCS). Higher scores of SCS indicate better self-regulation and impulse control.

UPPS-P Impulsive Behavior Scale (UPPS-P) includes 59 items rated on a 4-point Likert scale. Respondents indicate their agreement or disagreement with statements using a 4-point scale (1 = Agree Strongly, 4 = Disagree Strongly). Scoring involves calculating a mean score for each of the five subscales (scaled 1-4) and a total impulsivity score.

The Chinese version of the 5-item Morningness-Eveningness Questionnaire (rMEQ-5). The Chinese version of the MEQ-5 consists of five items selected from the Chinese version of the MEQ-19, namely items 1, 7, 10, 18, and 19.

The Barratt Impulsiveness Scale (BIS) consists of 30 items. Each item is rated according to the frequency of occurrence using a 4-point scoring method: rarely/never = 1, occasionally = 2, often = 3, and almost always/always = 4.

The Somatic Symptom Scale (SSS) consists of 20 items and is a self-report scale using a 4-point rating system (Table 1). A total raw score above 40 is considered positive.

The Behavioral Inhibition/Activation System Scale (BIS/BAS Scale) uses a 4-point scoring system, where 1 indicates "strongly agree" and 4 indicates "strongly disagree". Higher scores indicate greater activation of the behavioral inhibition system and behavioral activation system.