Psychotherapy in Patients With Endometriosis: Cognitive Behavioral Therapy Versus Acceptance and Commitment Therapy (T-ENDO)

October 31, 2026 updated by: Fiammetta Cosci

Testing Efficacy of Psychotherapeutic Interventions in Patients With ENDOmetriosis: A Randomized Controlled Trial Comparing Cognitive Behavioral Therapy vs Acceptance and Commitment Therapy

The aim of the present study is to compare two types of psychotherapeutic interventions in women with endometriosis and/or adenomyosis: cognitive behavioral therapy (CBT) and acceptance and commitment therapy (ACT). The study will examine whether these therapies differ in their effects on health-related quality of life. We hypothesis a different effect on health related quality of life pain-related difficulties, emotional well-being, fatigue, sexual functioning, and other aspects of daily life since the two interventions aim at different purposes and results. CBT is based on restructuring of thought, thus the aim and the result are activating a change. ACT is aimed at increasing acceptance of the existing condition in order to cope better with it. The literature indeed suggested that the two approach can produce different effects in the same clinical population.

The study will include women with a recent diagnosis and women who have been living with the diagnosis for a longer time.

Participants will be randomly assigned to receive either CBT or ACT. Both groups will attend eight therapy sessions, held every two weeks. Participants will complete online questionnaires before treatment, after session 4, after treatment, and 3 and 6 months after treatment. The questionnaires will assess quality of life, pain, emotional well-being, and other aspects of health and daily functioning.

The study will take place at the Endometriosis Centre of Careggi University Hospital in Florence, Italy. Eligible participants must be women aged 18 or older who are receiving care at this centre and have a confirmed diagnosis of endometriosis and/or adenomyosis based on medical assessment. They must have been on stable medication treatment for at least 3 months, speak and write Italian fluently, have internet access, and be able to provide informed consent. Women with a current psychiatric diagnosis or who are currently receiving psychotherapy are not eligible to participate in the study.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Endometriosis (ENDO) is a chronic inflammatory disease affecting 4-18% of women with symptoms such as dyspareunia, dysmenorrhea, dyschezia, low back pain, chronic pelvic pain and gastrointestinal manifestations. Meta-analyses showed higher anxiety, depression, and poorer quality of life in women with ENDO compared to healthy controls. Cross-sectional studies suggested that a psychological burden linked to pain and factors such as pain catastrophizing, low pain acceptance, self-criticism, psychological inflexibility (PI), maladaptive coping strategies, sexual dysfunction, maladaptive illness perceptions, early life adversity, negative body image, fatigue and low psychological flexibility. Long-term exposure to ENDO has been associated with an increased risk of developing more severe psychological distress over time. Therefore, accounting for time since diagnosis appears important when examining psychological outcomes in this population.

Psychological interventions such as psychoeducation, mindfulness-based techniques, acceptance and commitment therapy (ACT), and cognitive behavioral therapy (CBT) have shown promising results in improving pain, quality of life, anxiety, and depression in ENDO. However, this literature is sparse, and the methods used are heterogeneous. Furthermore, in these studies only pain, anxiety, depression, and quality of life have been investigated as outcomes measures although evidence from studies on other chronic illnesses and chronic pain conditions suggests that CBT and ACT interventions could also provide benefits in addressing self-criticism, eating-related psychopathology, psychological flexibility, maladaptive coping strategies, sexual dysfunction, maladaptive illness perceptions, fatigue, early life adversity, and negative body image. Furthermore, no studies to date have directly compared ACT-based and CBT-based interventions in women with ENDO. Given their different theoretical models and therapeutic targets, comparing the two interventions may help clarify their potential role in improving psychological adjustment and quality of life in ENDO.

Overall, studying the potential benefits of psychotherapeutic interventions based on CBT versus ACT components using rigorous methods, while accounting for illness duration, may help shed light on complementary therapeutic options for women with ENDO and on ways to modify their psychological burden trajectories, while also extending current knowledge by broadening the range of psychological outcomes assessed beyond commonly studied indicators such as pain, emotional distress, and quality of life.

The aim of the present study is to compare the effects of CBT-based versus ACT-based psychotherapeutic interventions on health-related quality of life in women with endometriosis and/or adenomyosis, considering both women with a recent diagnosis (≤12 months from diagnosis; Study 1) and those with a long-lasting diagnosis (>12 months from diagnosis; Study 2). This operational definition of "long-lasting" conditions is consistent with the literature on chronic illness adaptation, which conceptualizes the first year post-diagnosis as an early adjustment phase, whereas persistence beyond this period reflects a more established chronic illness trajectory and stabilized adaptation processes.

The study will also investigate the effects of the two interventions on a broad range of secondary outcomes in both Study 1 and Study 2, including endometriosis-specific quality of life, pain-related disability, psychological distress, psychological flexibility and related processes, coping strategies and emotion regulation, illness-related attitudes and perceptions, sexual functioning, life satisfaction, psychological well-being, and other clinical and psychological dimensions.

Study Type

Interventional

Enrollment (Estimated)

128

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Italy
    • FI
      • Florence, FI, Italy, 50134
        • Endometriosis Center, Department of Obstetrics and Gynecology, Careggi University Hospital (AOUC)
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • Age ≥ 18 years;
  • Access to internet and having an email address;
  • Diagnosis of endometriosis and/or adenomyosis based on gynecological assessment and imaging evaluation, in accordance with ICD-11 classification (WHO, 2019);
  • Seeking care at the Endometriosis Center (Department of Obstetrics and Gynecology at Careggi University Hospital (AOUC));
  • Ability to provide informed consent;
  • Fluency in written and spoken Italian;
  • Under stable pharmacological treatment for at least 3 months;
  • For Study 1: ≤12 months from diagnosis;
  • For Study 2: >12 months from diagnosis.

Exclusion Criteria:

  • Current psychiatric diagnosis assessed with the Structured Clinical Interview for DSM-5 (SCID-5; First et al., 2016);
  • Ongoing psychotherapeutic treatment.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Cognitive Behavioral Therapy (CBT)

CBT is a structured intervention targeting dysfunctional thoughts, emotions, and behaviors through psychoeducation, cognitive restructuring, behavioral strategies, and homework. As no standardized CBT protocol for endometriosis exists, this intervention was developed for this study based on CBT principles.

In Study 1, CBT comprises 8 biweekly sessions (4 psychoeducational and 4 CBT sessions) targeting physical pain (including central sensitization), mental pain and distress, relational and functional difficulties (including dyspareunia and fatigue), and maladaptive cognitions (catastrophizing, hopelessness, helplessness, and perfectionism).

In Study 2, CBT comprises 8 biweekly sessions: 4 core sessions addressing physical pain and dysfunctional thinking, mental pain and distress, relational and functional difficulties (including fatigue), and maladaptive cognitions. Each is followed by a consolidation session to review content and reinforce skills through behavioral exercises.
Behavioral: Cognitive Behavioral Therapy (CBT)

Cognitive behavioral therapy (CBT) delivered over 8 biweekly sessions, including psychoeducation, cognitive restructuring, behavioral strategies, and homework assignments. The intervention addresses physical pain, mental pain and psychological distress, relational and functional difficulties, and maladaptive cognitions. The session structure differs between Study 1 and Study 2.
Active Comparator: Acceptance and Commitment Therapy (ACT)

ACT promotes psychological flexibility and functioning despite distress through psychoeducation, experiential techniques, values-based action, and practice. As no standardized ACT protocol for endometriosis exists, this intervention was developed for this study based on ACT principles.

In Study 1, ACT comprises 8 biweekly sessions (4 psychoeducational, 4 ACT) targeting physical pain (including central sensitization), mental pain and distress, relational and functional difficulties (including dyspareunia and fatigue), and maladaptive cognitions (catastrophizing, hopelessness, helplessness, perfectionism).

In Study 2, ACT comprises 8 biweekly sessions: 4 core sessions address physical pain and an open response style, mental pain and distress, relational and functional difficulties (including fatigue), and maladaptive cognitions. Each is followed by a consolidation session reviewing content and introducing open, centered, and engaged response styles through experiential exercises.
Behavioral: Acceptance and Commitment Therapy (ACT)

Acceptance and commitment therapy (ACT) delivered over 8 biweekly sessions, including psychoeducation, experiential techniques, values-based action, and behavioral practice. The intervention addresses physical pain, mental pain and psychological distress, relational and functional difficulties, and maladaptive cognitions, while promoting psychological flexibility. The session structure differs between Study 1 and Study 2.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
EQ-5D-5L
Time Frame: change from baseline to 6-month follow up

The primary outcome will be health-related quality of life, assessed using the EQ-5D-5L (health states range from 11111, representing the best health state, to 55555, representing the worst health state).
change from baseline to 6-month follow up

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Endometriosis Health Profile Questionnaire (EHP-5)
Time Frame: change from baseline to 6-month follow up

Endometriosis Health Profile Questionnaire (EHP-5), with higher scores indicating worse endometriosis-related quality of life.
change from baseline to 6-month follow up
Brief Pain Inventory - Short Form (BPI-SF)
Time Frame: change from baseline to 6-month follow up

Brief Pain Inventory - Short Form (BPI-SF), with higher scores indicating greater pain-related disability.
change from baseline to 6-month follow up
Psychological Pain Index (PPI)
Time Frame: change from baseline to 6-month follow up

Psychological Pain Index (PPI), with higher scores indicating greater psychological pain.
change from baseline to 6-month follow up
Symptom Questionnaire (SQ)
Time Frame: change from baseline to 6-month follow up

Symptom Questionnaire (SQ), with higher scores indicating greater psychological distress.
change from baseline to 6-month follow up
Somatic Symptom Disorder - B Criteria Scale (SSD-12)
Time Frame: change from baseline to 6-month follow up

Somatic Symptom Disorder - B Criteria Scale (SSD-12), with higher scores indicating greater somatic symptom burden.
change from baseline to 6-month follow up
Pain Catastrophizing Scale (PCS)
Time Frame: change from baseline to 6-month follow up

Pain Catastrophizing Scale (PCS), with higher scores indicating greater pain catastrophizing.
change from baseline to 6-month follow up
Chronic Pain Acceptance Questionnaire (CPAQ)
Time Frame: change from baseline to 6-month follow up

Chronic Pain Acceptance Questionnaire (CPAQ), with higher scores indicating greater pain acceptance.
change from baseline to 6-month follow up
Multidimensional Psychological Flexibility Inventory (MPFI)
Time Frame: change from baseline to 6-month follow up

Multidimensional Psychological Flexibility Inventory (MPFI), with higher scores indicating greater psychological flexibility/inflexibility.
change from baseline to 6-month follow up
Acceptance and Action Questionnaire - II (AAQ-II)
Time Frame: change from baseline to 6-month follow up

Acceptance and Action Questionnaire - II (AAQ-II), with higher scores indicating greater psychological inflexibility.
change from baseline to 6-month follow up
Cognitive Fusion Questionnaire (CFQ)
Time Frame: change from baseline to 6-month follow up

Cognitive Fusion Questionnaire (CFQ), with higher scores indicating greater cognitive fusion.
change from baseline to 6-month follow up
Cognitive Emotion Regulation Questionnaire (CERQ)
Time Frame: change from baseline to 6-month follow up

Cognitive Emotion Regulation Questionnaire (CERQ), with higher scores indicating greater use of that specific emotion regulation strategy.
change from baseline to 6-month follow up
Satisfaction with Life Scale (SWLS)
Time Frame: change from baseline to 6-month follow up

Satisfaction with Life Scale (SWLS), with higher scores indicating greater life satisfaction.
change from baseline to 6-month follow up
World Health Organization-Five Well-Being Index (WHO-5)
Time Frame: change from baseline to 6-month follow up

World Health Organization-Five Well-Being Index (WHO-5), with higher scores indicating greater psychological well-being.
change from baseline to 6-month follow up
Illness Attitudes Scale (IAS)
Time Frame: change from baseline to 6-month follow up

Illness Attitudes Scale (IAS), with higher scores indicating more dysfunctional illness-related attitudes.
change from baseline to 6-month follow up
Brief Illness Perception Questionnaire (BIPQ)
Time Frame: change from baseline to 6-month follow up

Brief Illness Perception Questionnaire (BIPQ), with higher scores indicating more negative illness perceptions.
change from baseline to 6-month follow up
Female Sexual Function Index (FSFI)
Time Frame: change from baseline to 6-month follow up

Female Sexual Function Index (FSFI), with higher scores indicating better sexual functioning.
change from baseline to 6-month follow up
Chalder Fatigue Scale (CFS)
Time Frame: change from baseline to 6-month follow up

Chalder Fatigue Scale (CFS), with higher scores indicating greater fatigue.
change from baseline to 6-month follow up
Fatigue Severity Scale (FSS)
Time Frame: change from baseline to 6-month follow up

Fatigue Severity Scale (FSS), with higher scores indicating greater fatigue severity.
change from baseline to 6-month follow up
Beck Hopelessness Scale (BHS)
Time Frame: change from baseline to 6-month follow up

Beck Hopelessness Scale (BHS), with higher scores indicating greater hopelessness.
change from baseline to 6-month follow up
Demoralization Scale (Psychiatric Epidemiology Research Interview - PERI)
Time Frame: change from baseline to 6-month follow up

Demoralization Scale (Psychiatric Epidemiology Research Interview - PERI), with higher scores indicating greater demoralization.
change from baseline to 6-month follow up
Frost Multidimensional Perfectionism Scale (FMPS)
Time Frame: change from baseline to 6-month follow up

Frost Multidimensional Perfectionism Scale (FMPS), with higher scores indicating higher levels of perfectionism.
change from baseline to 6-month follow up
Somatosensory Amplification Scale (SSAS)
Time Frame: change from baseline to 6-month follow up

Somatosensory Amplification Scale (SSAS), with higher scores indicating greater somatic amplification.
change from baseline to 6-month follow up
Eating Disorder Inventory (EDI)
Time Frame: change from baseline to 6-month follow up

Eating Disorder Inventory (EDI), with higher scores indicating greater eating-related psychopathology.
change from baseline to 6-month follow up
Childhood Trauma Questionnaire - Short Form (CTQ-SF)
Time Frame: change from baseline to 6-month follow up

Childhood Trauma Questionnaire - Short Form (CTQ-SF), with higher scores indicating greater exposure to childhood trauma.
change from baseline to 6-month follow up
Social Readjustment Rating Scale (SRRS)
Time Frame: change from baseline to 6-month follow up

Social Readjustment Rating Scale (SRRS), with higher scores indicating greater exposure to stressful life events.
change from baseline to 6-month follow up

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Fiammetta Cosci

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

January 1, 2027

Primary Completion (Estimated)

September 30, 2028

Study Completion (Estimated)

October 31, 2028

Study Registration Dates

First Submitted

October 24, 2026

First Submitted That Met QC Criteria

October 24, 2026

First Posted (Actual)

October 30, 2026

Study Record Updates

Last Update Posted (Actual)

November 4, 2026

Last Update Submitted That Met QC Criteria

October 31, 2026

Last Verified

October 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • T-ENDO

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data will be shared upon request to the PI. Data can be shared as aggregated, anonymized information.

IPD Sharing Time Frame

From 01.01.2030 to 31.12.2030

IPD Sharing Access Criteria

Researchers will be able to access.

IPD Sharing Supporting Information Type

  • ICF
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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