Brief Group Intervention Based on Acceptance and Commitment Therapy (ACT) for Problem Gambling: A Pilot Study
Phase: NA
Conditions: Problem Gambling
Sponsor: Universidad Europea de Madrid

 
 
 
 
 
 
Brief Group Intervention Based on Acceptance and Commitment Therapy 
(ACT) for Problem Gambling: A Pilot Study 
 
ID: 2025-81 
Document date: February 23, 2025 
Principal Investigators: Francisco Montesinos, Ph.D.- David Lobato, Ph.D. 
Study Protocol and Statistical Analysis Plan 
 
 

Study Protocol 
Objective 
To examine the preliminary feasibility and acceptability of a brief group-based 
psychological intervention grounded in Acceptance and Commitment Therapy (ACT), aimed 
at young individuals exhibiting problematic gambling behaviors. 
Design 
Open label pilot study 
Methods 
After receiving detailed information about the structure and characteristics of the study, 
participants who provide written informed consent will undergo individual assessments to 
determine their eligibility. The assessment will include a structured interview and 
standardized questionnaires. Eligible participants will complete standardized 
questionnaires both before and after the intervention. The sample will consist of five 
participants who will receive an online group-based psychological treatment comprising 
eight weekly sessions, each lasting approximately 90 minutes. 
Intervention Protocol 
Session 1: Introduction to ACT and Values Clarification 
Through metaphors and experiential exercises, such as the “garden” metaphor, participants 
will explore meaningful life domains (e.g., family, relationships, health, education/work, 
leisure) that may have been overshadowed by gambling behavior. 
Session 2: Acceptance and Cognitive Defusion 
Participants will be trained in cognitive defusion and acceptance strategies using exercises 
such as “the mind narrator,” aimed at altering their relationship with automatic gambling-
related thoughts. 
Session 3: Mindfulness 
Mindfulness practices focused on present-moment awareness, such as the “body scan” and 
“conscious breathing,” will be introduced to help participants observe their thoughts, 
emotions, and bodily sensations without immediate reaction. This skill is expected to 
enhance recognition of gambling-related impulses and improve emotional regulation. 
Session 4: Establishing the Observer Self Perspective 
The session will address how individuals identify with self-labels and narratives that foster 
hopelessness. Experiential exercises will be used to cultivate a more flexible and expansive 
perspective, reducing the influence of these narratives on behavior. 

Session 5: Committed Action and Goal Setting 
Participants will work on identifying and formulating concrete personal goals aligned with 
their values. Strategies will be developed to support deliberate action toward these goals, 
even in the presence of emotional discomfort or gambling urges. 
Session 6: The Trap of Experiential Avoidance and Psychological Flexibility 
The session will explore how gambling may serve as an escape from difficult emotions such 
as sadness, anxiety, or guilt. Through metaphors and experiential exercises, participants 
will be trained to remain in contact with these complex emotions without avoidance, 
thereby expanding their repertoire for coping with distress. 
Session 7: Committed Action and Overcoming Barriers 
Internal and external barriers to value-consistent action—such as gambling urges, fear of 
failure, or aversive thoughts (e.g., “there’s no point in trying,” “I’m sure I can’t do it”)—will 
be identified. Practical exercises will be used to train flexible responses to these barriers. 
Session 8: Consolidation and Maintenance Planning 
Key learnings will be reviewed, and an individualized action plan will be developed to 
sustain commitment to value-driven actions in the medium and long term. Potential risk 
situations that may trigger gambling urges will be identified, and coping strategies will be 
practiced. 
Statistical Analysis Plan (SAP) 
Given the exploratory nature of the study and the small sample size, non-parametric tests 
will be employed to analyze the results (pre-, post-, and follow-up group mean 
comparisons). An analysis of variance will be conducted to determine the specific 
contribution of each independent variable and potential interactions among them. 
Additionally, the Jacobson and Truax (1991) method will be applied to estimate the clinical 
significance of the intervention effects.