Brief Trial of ACT-i for Adults With Chronic Insomnia

April 3, 2026 updated by: Roxana Cardos, Babes-Bolyai University

Brief Group Acceptance and Commitment Therapy for Insomnia: Study Protocol for a Randomized Controlled Trial

This is a prospective, randomized-controlled trial that assesses the efficacy of a brief Acceptance and Commitment Therapy (ACT-i), compared to an attentional control group, in adults with chronic insomnia. The interventions will be evaluated for their impact on insomnia severity, cognitive function, depression, anxiety, psychological flexibility, and sleep beliefs - measured before treatment, two weeks after and at a three-month follow-up.

Study Overview

Detailed Description

Insomnia is the most prevalent sleep disorder. It is associated with impairments both physically and psychologically. Therefore, it usually causes a suite of durable stressors in numerous aspects of life, such as academically, professionally, socially, and financially. Given its widespread impact, early effective treatments are crucial to prevent long-term consequences.

The first line of treatment is Cognitive-Behavioral Therapy for Insomnia (CBT-i). Despite its effectiveness, approximately 60% of individuals with chronic insomnia and comorbidities do not go into remission after treatment or simply do not adhere to it. Acceptance and Commitment Therapy for Insomnia (ACT-i) has great potential for overcoming this limitation, as it focuses on accepting the feelings and thoughts associated with insomnia, through value-based actions. However, more studies on ACT-i as a monotherapy are needed.

This study aims to evaluate the efficacy of brief, group ACT-i for chronic insomnia in adults, versus an attentional control group. Participants will be aged between 18 and 59 years, diagnosed with chronic insomnia who will be randomly assigned to either ACT-i, or the control group. To limit age-related sleep changes, only participants aged up to 59 will be included, as sleep difficulties tend to increase after the age of 60. The interventions will be performed in groups, in 2 weekly sessions. Their effects will be investigated for the primary outcome related to the severity of insomnia, and secondary outcomes related to depression, anxiety, cognitive functioning, psychological flexibility, and beliefs about sleep at pre-test, post-test at two weeks and three-month follow-up. After the interventions, participants will complete an inventory regarding the adherence and satisfaction to both interventions. This is the first attempt to investigate a group-based ACT-i as monotherapy with an attentional control group delivered in an accessible, brief-group format. Specifically, the sessions are implemented briefly in 2 group sessions, unlike other studies that have (at least) 4 group sessions. Furthermore, the investigators will also compare their adherence rates and patients' satisfaction.

Study Type

Interventional

Enrollment (Estimated)

76

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 Locations

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

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • clinical/ subclinical diagnosis of chronic insomnia either already diagnosed by a professional, or identified with SCISD-R by our team of clinicians
  • age over 18 and older, but not over 59 years old;
  • minimal/ mild symptomatology of depression (scores ≤ 9 on PHQ-9) and/ or anxiety (scores ≤ 9 on GAD-7) or as diagnosed with SCID-5-CV;

Exclusion Criteria:

  • diagnosed with a neurological degenerative disorder, or any moderate/ severe psychiatric disorder;
  • diagnosed with other sleep disorder (e.g., sleep apnea, restless legs/ periodic limb movements, circadian-based sleep disorder);
  • diagnosed with cognitive impairments;
  • unable to understand Romanian;
  • unable to attend to online-sessions (e.g., no laptop, microphone, camera);

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: Acceptance and Commitment Therapy for Insomnia (ACT-i)

The intervention is available in its individual and group format, which can be adapted to an online context in "Acceptance and Commitment Therapy for Insomnia: A Session-By-Session Guide", by Renatha El Rafihi-Ferreira (Rafihi-Ferreira, 2024). It comprises the details of each ACT-i group session with illustrations and examples for the trained therapists.

Participants will be requested to register to an Online Platform, such as Google Meet, to attend the two sessions which will be guided by a trained therapists. Each session will have approximately 120 minutes. They will receive instructions from the therapists and handouts at the end of each session. Facilitators will receive training from a specialized mental health professional.

Monotherapy ACT-i, with no behavioral components, is a brief and low-intensity treatment that has recently been detailed by experts in the field in a session-by-session guideline, intending to help people affected by chronic insomnia. The key components of the sessions are psychoeducation, mindfulness, values and actions derived from chosen values, and defusion.

An adapted, brief and online version of the intervention was developed by the authors of this study. Both interventions were matched in terms of overall duration and delivery format. Each session was tailored to follow a comparable format. Therapeutic alliance, psychoeducation, sleep hygiene, relaxation training and homework was targeted in the first session. In the second session, ACT-i focused on values, acceptance strategies and psychological flexibility. This version will be published online upon request. Each session will last 120 min. They will be delivered once per week, for two consecutive weeks.

Active Comparator: Attentional Control Group
Participants will receive this intervention in an online platform by a trained professional. His training will be provided by a mental health expert with experience in carrying out psychoeducational and non-directive group sessions. This group will match the ACT-i intervention in terms of session duration, delivery format, group interaction, facilitator contact, time and handouts/ homework.
The focus of the sessions will be on participants, on general topics. It will not include any active, psychological intervention components, such as cognitive restructuring or ACT processes. No recommendations or psychological guidance will be given. Each session will last 120 minutes. It will be held once per week, for two weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in the score of Insomnia Severity Index (ISI);
Time Frame: baseline, 2 weeks after the intervention
The Insomnia Severity Index (ISI) is a brief tool of chronic insomnia. It consists of 7 items about the severity of insomnia, its noticeability, and daytime functioning. Total scores range from 0 to 28, with higher scores reflecting more severe clinical insomnia.
baseline, 2 weeks after the intervention

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in the score of Insomnia Severity Index (ISI)
Time Frame: 3 months after the intervention
Follow-up evaluation of the severity of insomnia using ISI
3 months after the intervention
Change in the score of Patient Health Questionnaire-9
Time Frame: 3 months after the intervention
The Patient Health Questionnaire-9 (PHQ-9) is a brief tool of depression. It consists of 9 items about depressive symptomatology, such as anhedonia, sadness and fatigue. Total scores range from 0 to 27.
3 months after the intervention
Change in the score of Multidimensional psychological flexibility inventory (MPFI-24; Gregoire et al., 2020)
Time Frame: 3 months after the intervention
The Multidimensional psychological flexibility inventory (MPFI-24) is a 24-item measure of psychological flexibility, including acceptance, mindfulness, and values-based actions. Total scores range from 24 to 144.
3 months after the intervention
Change in the score of the Dysfunctional Beliefs and Attitudes about Sleep (DBAS-16)
Time Frame: 3 months after the intervention
The Dysfunctional Beliefs and Attitudes about Sleep (DBAS-16) is a 16-item scale measuring dysfunctional sleep-related cognitions. Total score is added up and divided by 16, and a higher score represents higher unrealistic expectations regarding sleep.
3 months after the intervention
Change in the score of The Cognitive Failures Questionnaire (CFQ)
Time Frame: 3 months after the intervention
The Cognitive Failures Questionnaire (CFQ) is a self-report tool of the frequency of daily cognitive failures, such as forgetfulness or lapses in attention. It has 25 items and total scores range from 0 to 100, with higher scores indicating more subjective cognitive failure.
3 months after the intervention
Change in the score of Barkley Deficits in Executive Functioning Scale (BDEFS-SF)
Time Frame: 3 months after the intervention
The Barkley Deficits in Executive Functioning Scale (BDEFS-SF) is a 20-item self-report measure of executive functioning deficits. Each item is rated on a 4-point Likert scale, ranging from 1 ("never or rarely") to 4 ("very often"). Total scores range from 20 to 80.
3 months after the intervention
Change in the score of The Generalised Anxiety Disorder 7 (GAD-7)
Time Frame: 3 months after the intervention
The Generalised Anxiety Disorder 7 (GAD-7) is a 7-item self-report measure of the severity of anxiety. Each item is rated on a 4-point Likert scale, ranging from 0 ("not at all") to 4 ("nearly every day"). Total scores range from 20 to 80.
3 months after the intervention

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Satisfaction: Client Satisfaction Questionnaire (CSQ-8)
Time Frame: one day after the intervention, 3 months after the intervention
The Client Satisfaction Questionnaire (CSQ-8) is a brief tool of general satisfaction with the treatment being given. Each item is rated on a 4-point scale, ranging from 1 ("weak") to 4 ("excellent"). Total scores range from 8 to 32, with higher scores reflecting greater satisfaction.
one day after the intervention, 3 months after the intervention
Adherence: Adherence and satisfaction questionnaire (Ferreira et al., 2024)
Time Frame: one day after the intervention, 3 months after the intervention
Adherence and satisfaction questionnaire is a brief self-report tool of adherence and satisfaction with the provided treatment. It has 8 items, with yes and no answers.
one day after the intervention, 3 months after the intervention

Collaborators and Investigators

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

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 (Actual)

May 23, 2025

Primary Completion (Estimated)

May 1, 2026

Study Completion (Estimated)

June 1, 2026

Study Registration Dates

First Submitted

May 20, 2025

First Submitted That Met QC Criteria

June 30, 2025

First Posted (Actual)

July 2, 2025

Study Record Updates

Last Update Posted (Actual)

April 7, 2026

Last Update Submitted That Met QC Criteria

April 3, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Will share IPD used in the results of the publication, upon request.

IPD Sharing Time Frame

The IPD may be shared after publication upon request, with no end date.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

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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