This randomized controlled trial evaluated the efficacy of a cognitive behavioral intervention based on lucid dreaming training and imagery control therapy for reducing REM-related symptoms in patients with narcolepsy type 1. Specifically, the study examined the impact of the intervention on hypnagogic hallucinations and sleep paralysis, which are common and distressing symptoms associated with REM sleep intrusions in narcolepsy.

Ninety-eight adults with confirmed narcolepsy type 1 were randomly assigned to either an experimental intervention group or a control group receiving standard pharmacological treatment, structured clinical follow-up, and sleep hygiene psychoeducation. The intervention consisted of six weekly 90-minute telehealth sessions integrating psychoeducation, dream awareness training, lucid dreaming induction techniques, imagery rehearsal therapy (IRT), metacognitive strategies, emotional regulation, and relapse prevention.

Primary outcomes included changes in the frequency and distress associated with hypnagogic hallucinations and sleep paralysis. Secondary outcomes included subjective sleep quality, metacognitive dream-related variables, and quality of life. Participants were assessed at baseline, post-treatment, and at 6- and 12-month follow-up evaluations.

The study aimed to determine whether behavioral interventions targeting dream awareness, emotional regulation, and metacognitive control could complement pharmacological treatment and improve REM-related symptoms and sleep-related quality of life in narcolepsy.

Detailed Description

Narcolepsy type 1 is a chronic neurological sleep-wake disorder characterized by excessive daytime sleepiness, cataplexy, and REM sleep dissociation phenomena, including hypnagogic hallucinations and sleep paralysis. Although pharmacological therapies are effective for managing daytime sleepiness and cataplexy, treatment options for REM-related perceptual symptoms remain limited. Hypnagogic hallucinations and sleep paralysis are frequently associated with emotional distress, impaired quality of life, anxiety, and sleep disruption.

Lucid dreaming refers to the awareness of dreaming while the dream is occurring and may involve the ability to voluntarily influence dream content. Previous studies have suggested that lucid dreaming training and imagery-based cognitive techniques may reduce emotional distress associated with nightmares and other disturbing dream experiences. Given the high prevalence of lucid dreaming experiences among patients with narcolepsy, these strategies may represent a promising behavioral approach for REM-related symptoms.

This study was designed as a randomized controlled longitudinal trial to evaluate the efficacy of a cognitive behavioral intervention integrating lucid dreaming training and imagery control therapy in patients with narcolepsy type 1. The study was conducted between March 2023 and April 2025 using synchronous telehealth sessions delivered through a secure videoconferencing platform.

A total of 98 participants with clinically and polysomnographically confirmed narcolepsy type 1 were recruited from specialized sleep medicine centers in Colombia and Costa Rica. Eligible participants were adults presenting clinically significant hypnagogic hallucinations and/or sleep paralysis and receiving stable pharmacological treatment. Participants with severe psychiatric disorders, dissociative disorders, or active substance use disorders were excluded.

Participants were randomly assigned to one of two groups:

Experimental group (n = 49): received six weekly 90-minute sessions of cognitive behavioral therapy for narcolepsy (CBT-NAR) integrating lucid dreaming training and imagery control therapy in addition to stable pharmacological treatment.

Control group (n = 49): continued standard pharmacological treatment with structured clinical follow-up and sleep hygiene psychoeducation focused on sleep-wake regularity, scheduled naps, healthy sleep habits, and general education about narcolepsy.

The intervention was delivered by trained clinical psychologists specialized in behavioral sleep medicine. Treatment components included:

Psychoeducation about narcolepsy and REM-related symptoms. Dream diary monitoring and dream awareness training. Lucid dreaming induction and maintenance techniques. Reality testing and metacognitive strategies. Imagery rehearsal therapy (IRT) and imagery restructuring techniques. Emotional regulation and coping strategies within lucid dreams. Relapse prevention and guided autonomous practice.

Primary outcomes were reductions in the frequency and distress associated with hypnagogic hallucinations and sleep paralysis. Secondary outcomes included subjective sleep quality assessed with the Pittsburgh Sleep Quality Index (PSQI), narcolepsy symptom severity assessed with the Narcolepsy Severity Scale (NSS), dream-related metacognitive variables assessed with the LUCID Scale, and quality of life assessed with the SF-36 questionnaire.

Assessments were conducted at baseline, post-treatment, 6-month follow-up, and 12-month follow-up. Statistical analyses included descriptive statistics, Student's t-tests, Cohen's d effect sizes, mixed-effects longitudinal models, and multiple linear regression analyses. Missing data were handled under the missing-at-random assumption using mixed-effects modeling.

The study hypothesized that systematic lucid dreaming training and imagery control techniques would reduce the frequency and emotional distress associated with REM-related symptoms while improving sleep quality, emotional regulation, and quality of life. Preliminary findings demonstrated clinically significant and sustained reductions in REM-related symptoms, improvements in dream-related metacognitive variables, and better subjective sleep quality and emotional well-being in the intervention group compared with controls.

Inclusion Criteria:

• Adults aged ≥18 years diagnosed with Narcolepsy Type 1, confirmed by clinical evaluation and polysomnography.
• Experiencing clinically significant hypnagogic hallucinations and/or sleep paralysis.
• Stable pharmacological treatment for narcolepsy, such as modafinil and/or methylphenidate.
• Able and willing to provide informed consent electronically.
• Available to participate in six weekly virtual intervention sessions.
• Willing to adhere to structured medical follow-up, including sleep hygiene education, nap guidance, sleep habit stabilization, and participation in sleep schedule programs.

Exclusion Criteria:

• Presence of severe psychiatric disorders or dissociative disorders. Active use of psychoactive substances during the study period.
• Participation in other interventions targeting lucid dreaming or imagery rehearsal during the trial.
• Any medical or cognitive condition that, in the investigator's judgment, would interfere with participation or adherence to the intervention.

There is no plan to share individual participant data (IPD). In accordance with Colombian regulations on personal data protection and processing (Law 1581 of 2012 and related regulations), clinical and sensitive participant information is protected under strict confidentiality, privacy, and restricted data handling principles. Access to study data will be limited to authorized members of the research team and relevant regulatory or ethics authorities, in compliance with applicable regulations and the informed consent provided by participants.

(Participants and care providers were not blinded because of the behavioral nature of the intervention, but outcome evaluators and the statistical analyst remained blinded to group allocation.)