Body-Focused Mindfulness as an Add-on Intervention in Inpatient Alcohol Use Disorder Treatment (MBI-AUD-PL) (MBI-AUD-PL)

BACKGROUND Alcohol use disorder (AUD) is associated with impaired interoceptive awareness, bodily dissociation, alexithymia, and emotion dysregulation. These deficits are linked to elevated craving and relapse risk. Impaired body-self integration - the degree to which individuals identify with their own body - has been documented in AUD and is associated with emotional processing difficulties. While mindfulness-based interventions have shown promise in AUD treatment, programs targeting bodily experience without direct reference to substance use have not been systematically evaluated in inpatient settings.

INTERVENTION The body-focused mindfulness intervention consists of 6 weekly 90-minute group sessions added to standard inpatient AUD treatment. Each session follows a structured format: check-in and review of home practice (10 min), breath-focused meditation (10 min), psychoeducation on mindfulness attitudes (15 min), main body-focused practice - body scan in lying or seated position, mindful walking and stretching (20 min), structured inquiry (15 min), weekly intention setting and home practice assignment (10 min), and 3-minute breathing space (5 min). Participants receive audio recordings of guided mindfulness exercises and are encouraged to practice independently (5-10 minutes daily) between sessions. The intervention does not include direct reference to alcohol use or relapse prevention content. Sessions are delivered by therapists trained in mindfulness-based approaches with personal meditation practice experience.

STRUCTURED INQUIRY Each session includes a structured inquiry component in which the therapist facilitates exploration of participants' bodily experience during practice through open, non-judgmental questions. Inquiry is anchored to bodily experience - the therapist actively returns the conversation to somatic sensations when participants shift toward narrative or abstract reflection.

CONTROL CONDITION The active comparator group receives 6 weekly 90-minute psychoeducation sessions added to the same standard inpatient AUD treatment. Sessions cover standard topics related to alcohol use disorder, recovery, and coping strategies. Delivered by the same therapists as the experimental group. All other components of the inpatient treatment program are identical between groups.

RANDOMIZATION Randomization occurs after 14 days of hospitalization, following completion of the standard introductory psychoeducation program. Computer-generated randomization with sequentially numbered sealed envelopes is used for allocation concealment. Randomization is performed by a person not involved in the delivery of the intervention or outcome assessment.

ASSESSMENT All assessments are conducted in paper-and-pencil format at five time points: baseline (T0, after 14 days of hospitalization, before randomization), post-intervention (T1, before discharge, approximately 6 weeks after T0), and follow-up at 4 weeks (T2), 6 months (T3), and 12 months (T4) post-discharge. After each session, participants in both groups complete a brief paper-based questionnaire consisting of three numeric rating scale items (0-10) covering mindful awareness during the session, clarity of bodily sensations during the session, and current alcohol craving.

BODY MAPS Bodily sensation phenomenology is assessed using a paper-based body mapping measure adapted from the InteroMaps framework. Participants mark bodily regions on printed body outlines (front and back views of the whole body and of the head), indicating the intensity of sensations by the number of crosses placed in a region (1 = very weak to 5 = very strong) and rating the pleasantness of each marked sensation on a 1 to 7 scale (1 = very unpleasant, 4 = neutral, 7 = very pleasant). At T0 and T1, participants complete body maps for eight states: happiness, fear, anger, sadness, disgust, surprise, shame, and a neutral state.

SAMPLE SIZE Sample size was estimated based on a pre-registered meta-analysis of 29 randomized controlled trials (N=2,191) examining the effects of mindfulness-based interventions on self-reported interoception (primary outcome: MAIA-2 total score). The pooled effect across all mindfulness interventions was g=0.31 (95% CI [0.21, 0.42]); the effect for mindfulness-based programs incorporating body scan, breath awareness, mindful movement, and inquiry was g=0.41 (95% CI [0.29, 0.54]). Adopting g=0.41 as the primary assumption, with alpha=0.05 (two-tailed) and 80% statistical power, the required sample is 95 participants per group (N=190 total). Accounting for an anticipated 20% dropout rate, the adjusted target is 119 per group. The planned sample of N=240 (120 per group) provides 80% power at g=0.41 after accounting for dropout, with additional margin for feasibility.

FEASIBILITY REVIEW After enrollment of 100 participants, a feasibility review will assess recruitment rate, protocol adherence, and dropout rate. No interim efficacy analysis is planned. Sample size may be revised upward based on observed attrition. Recruitment will continue beyond N=240 if feasible within the planned recruitment period.