Acceptance and Commitment Therapy on Psychological Flexibility, Values, and Well-Being: A Single-Case Experimental Study

N/ACompletedNCT07620483

Universidad del Valle, Colombia12 enrolled

Overview

The goal of this clinical trial is to evaluate the effects of a brief Acceptance and Commitment Therapy (ACT)-based group intervention on psychological flexibility, values-based functioning, and psychological well-being in university students aged 18 to 28 years presenting elevated levels of emotional distress and psychological risk indicators. The main questions it aims to answer are: Does a brief ACT-based intervention reduce experiential avoidance and cognitive fusion in university students? Does the intervention improve present-moment awareness, values-based functioning, life satisfaction, and psychological flourishing? Participants will: Complete repeated self-report assessments across 13 measurement points distributed throughout baseline, intervention, and follow-up phases. Participate in five weekly ACT-based group intervention sessions delivered by trained clinical psychologists. Engage in experiential ACT exercises focused on acceptance, mindfulness, cognitive defusion, values clarification, and committed action. Complete between-session activities and behavioral practices related to the ACT processes addressed during the intervention. Participate in follow-up assessments to evaluate maintenance of treatment effects over time.

University students frequently experience elevated levels of emotional distress, including symptoms of anxiety, depression, stress, worry, and psychological maladjustment. Brief interventions based on Acceptance and Commitment Therapy (ACT) have shown promising results in reducing experiential avoidance and cognitive fusion while promoting psychological flexibility and well-being. The present study evaluates the effects of a brief ACT-based intervention protocol delivered in a group format using a Single-Case Experimental Design (SCED) with repeated measurements across baseline, intervention, and follow-up phases. The intervention focuses on core ACT processes, including acceptance, cognitive defusion, present-moment awareness, values clarification, and committed action. Participants completed repeated assessments of psychological flexibility processes and well-being indicators across thirteen measurement points distributed throughout the study phases. The investigators hypothesize that the ACT-based intervention will produce reductions in experiential avoidance and cognitive fusion, together with improvements in present-moment awareness, values-based functioning, life satisfaction, and flourishing.

Study Type

INTERVENTIONAL

Allocation

Interventions

Acceptance and Commitment Therapy (ACT)-Based Brief Group InterventionBEHAVIORAL

The intervention consisted of a brief group-based Acceptance and Commitment Therapy (ACT) protocol designed to promote psychological flexibility and psychological well-being in university students presenting elevated emotional distress and psychological risk indicators. The protocol was grounded in the functional contextual approach and targeted core ACT processes, including acceptance, cognitive defusion, present-moment awareness, values clarification, and committed action. Participants were organized into small groups of 5 to 8 individuals and attended five weekly intervention sessions conducted by trained clinical psychologists with at least five years of clinical experience. Prior to implementation, therapists completed specialized ACT training delivered by an expert clinician with extensive experience in Acceptance and Commitment Therapy. The intervention protocol included an initial preliminary session focused on motivational engagement, informed consent procedures, feedback rega

Eligibility

Sex: ALLMin age: 18 YearsMax age: 28 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: University students aged 18 years or older Interest in strengthening mental health and psychological well-being Voluntary agreement to participate in the study High-risk scores on at least one of the following screening instruments: Depression Anxiety Stress Scales (DASS-21) General Health Questionnaire (GHQ-12) State Worry Questionnaire-11 (SWQ-11) Exclusion Criteria: Current psychological or psychiatric treatment Current use of psychiatric medication Diagnosis related to developmental or learning difficulties Failure to attend intervention sessions Incomplete participation in study assessments

Outcomes

Primary Outcomes

Mindful Attention Awareness Scale (MAAS)

The Mindful Attention Awareness Scale (MAAS) is a 15-item self-report questionnaire designed to assess present-moment attention and awareness in daily life. Items are rated on a 6-point Likert-type scale ranging from 1 ("almost always") to 6 ("almost never"). Total scores are calculated by summing item responses, with higher scores indicating greater mindfulness and present-moment awareness.

Time frame: Weekly during baseline (4 weeks), intervention (6 weeks), and follow-up (3 weeks), up to 13 weeks

Acceptance and Action Questionnaire-II (AAQ-II)

The Acceptance and Action Questionnaire-II (AAQ-II) is a 7-item self-report questionnaire designed to assess experiential avoidance and psychological inflexibility. Items are rated on a 7-point Likert-type scale ranging from 1 ("never true") to 7 ("always true"). Total scores are calculated by summing item responses, with higher scores indicating greater experiential avoidance and psychological inflexibility.