Development of a mindfulness-based intervention for narcolepsy: a feasibility study

Abstract

Study Objectives

Mindfulness-based interventions (MBI) have been shown to improve psychosocial functioning in medical populations but have not been studied in narcolepsy. This study examined the feasibility and acceptability of an MBI that was adapted for narcolepsy, including three variations in program length.

Methods

Adults with narcolepsy (N = 60) were randomized to MBI groups of varying durations: brief (4 weeks), standard (8 weeks), or extended (12 weeks). Participants completed assessments at baseline, 4, 8, and 12 weeks. To assess feasibility and acceptability, primary outcomes included attendance, meditation practice, and data completeness. Additionally, participants completed measures of mindfulness, self-compassion, mood, sleep, psychosocial functioning, and cognition. An effect size of Cohen’s d ≥ 0.5 was used as the prespecified benchmark for a minimal clinically important difference (MCID).

Results

The attendance, meditation, and data completeness benchmarks were met by 71.7%, 61.7%, and 78.3% of participants, respectively. Higher proportions of the brief and extended groups met these benchmarks compared to the standard group. All groups met the MCID for mindfulness, self-compassion, self-efficacy for managing emotions, positive psychosocial impact, global mental health, and fatigue. Standard and extended groups met the MCID for anxiety and depression, and extended groups met the MCID for additional measures including social and cognitive functioning, daytime sleepiness, hypersomnia symptoms, and hypersomnia-related functioning.

Conclusions

Results suggest that the remote delivery and data collection methods are feasible to employ in future clinical trials, and it appears that the extended MBI provides the most favorable clinical impact while maintaining attendance and engagement in meditation practice.

Clinical Trial Registration

Awareness and Self-Compassion Enhancing Narcolepsy Treatment (ASCENT), NCT04306952, https://clinicaltrials.gov/ct2/show/NCT04306952

Graphical Abstract

Graphical Abstract.

Statement of Significance.

Narcolepsy is a central disorder of hypersomnolence that profoundly affects health-related quality of life, including mood, relationships, occupational functioning, and daily activities. Current treatments do not adequately address these psychosocial impacts. This study therefore examined the feasibility of a mindfulness-based intervention (MBI) designed to improve psychosocial functioning in adults with narcolepsy. Mindfulness has previously been shown to improve functioning in various medical conditions but has not been applied to narcolepsy. Three lengths of MBI were tested, and the results demonstrated support for the feasibility and acceptability of the MBIs. Additionally, participants demonstrated improvement in psychosocial outcomes including mindfulness, self-compassion, self-efficacy for managing emotions, and mental health. Based on this preliminary data, future research should examine the efficacy of MBI for improving psychosocial functioning in people with narcolepsy.

Narcolepsy is a central disorder of hypersomnolence (CDH) that profoundly affects health-related quality of life (HRQoL) and currently has no cure. People with narcolepsy (PWN) report significant impairments in HRQoL and daily functioning [1–6], including emotional [4, 7, 8] and interpersonal distress [9]. Compared to matched controls, PWN have two to four times the rate of mood and anxiety disorders and significantly higher work absenteeism [10]. These symptoms are persistent, with 25% of PWN reporting stable levels of moderate to severe symptoms of depression over a 5-year period [7]. Moreover, mental health symptoms appear to be related to social stigma. Kapella et al. [11] found that young adults 18–35 years old with narcolepsy perceived significantly more health-related stigma, lower mood, and worse HRQoL compared to young adults without narcolepsy, and health-related stigma was associated with lower functioning both directly and indirectly through depressed mood. An FDA report from a 2013 public meeting on Narcolepsy Patient-Focused Drug Development [12] revealed that “loss of control” and the social stigma of being called “lazy” affected HRQoL. These findings highlight the need to address mental health and particularly psychosocial functioning in the management of narcolepsy.

Unfortunately, although current treatments are often effective at managing narcolepsy symptoms, they do not adequately address HRQoL. The AASM clinical practice guideline for CDH [13] recommends pharmacotherapy as the primary treatment for narcolepsy, but one study found that 28.8% still reported ongoing moderate to severe depression despite taking medications for CDH [14]. The practice guideline acknowledged that additional non-pharmacological approaches might be needed for optimal treatment, but there is little evidence to guide such an approach. A recent study found that standard psychotherapy (e.g. CBT for depression or anxiety) failed to effectively address mental health needs within the context of narcolepsy [15]. Specifically, PWN in that study reported that many psychotherapists lacked adequate training in narcolepsy, which led to low rapport, and symptoms of narcolepsy (e.g. excessive daytime sleepiness) limited participants’ ability to engage in treatment recommendations. In addition, available treatments did not appropriately address the social aspects of narcolepsy, such as social stigma, and PWN expressed a desire to interact with other PWN. These shortcomings reveal an important clinical gap in the care of PWN.

Complementary medicine has been shown to be an effective adjunctive tool for managing disease-related impacts in other chronic medical illnesses (e.g. chronic pain and cancer) and could provide a novel approach for improving HRQoL in PWN. Specifically, mindfulness-based interventions (MBIs) are mind-body programs that teach mindfulness meditation as a health behavior to regulate emotion and cope with stress. Several reviews and meta-analyses have revealed a positive benefits-to-risks profile for MBIs with medium to large pre-to-post effect sizes for symptoms of anxiety and depression (Hedge’s g = 0.55 to 0.97) that are comparable to antidepressant medications with fewer adverse effects [16, 17]. Given evidence that MBIs can improve anxiety and depression in medical populations, this approach has the potential to improve mood symptoms which are commonly comorbid in PWN. Additionally, cultivating self-compassion via mindfulness practices may allow PWN to better cope with health-related stigma, and mindful awareness of narcolepsy symptoms may also lead to improved self-efficacy in managing symptoms. Together, these potential benefits of MBI may improve daily functioning and HRQoL for PWN.

Observational data also indicate that an MBI is likely to be acceptable among PWN, as survey studies conducted in the United States and Germany have found that 20%–39% of PWN practice meditation and 19%–33% practice yoga [8, 18]. However, it is unclear how often PWN use these practices or whether these practices are effective in improving psychosocial functioning. Finally, MBI programs have high potential for scalability and dissemination, as they are typically taught by non-specialists/non-clinicians and can be provided remotely. Together, these indications support the systematic development and evaluation of MBIs to improve psychosocial functioning and HRQoL as a complement to pharmacotherapy for PWN.

The present study was a randomized feasibility trial to identify the optimal parameters for adapting and delivering an MBI for PWN. The first aim was to evaluate the feasibility and acceptability of telehealth-delivered MBI for PWN using prespecified benchmarks to evaluate participant enrollment, participant engagement, and completeness of study data. Given the barriers and challenges previously encountered by PWN [15], we sought to address these shortcomings by incorporating these considerations into the design of the intervention and study protocol. The second aim was to examine the clinical impact of three versions of MBI with varying “doses”: 4-week MBI (brief), 8-week MBI (standard), or 12-week MBI (extended). The rationale for testing these doses is due to uncertainty about the most appropriate way to deliver an MBI program given the potential interference of narcolepsy symptoms on sustained attention and concentration. The findings from this study are intended to serve as a proof of concept for conducting a randomized controlled trial to test the efficacy of MBI for improving HRQoL as a complementary practice to standard care for narcolepsy.

Materials and Methods

Participants and procedures

Participants were adults (≥18 years old) living in the United States who had been diagnosed with narcolepsy type 1 (NT1) or narcolepsy type 2 (NT2), were receiving standard medical care for their narcolepsy, and demonstrated psychological distress (T-score ≥60 on the patient-reported outcomes measurement information system (PROMIS) Depression or Anxiety scale [19]). Individuals were excluded for the following reasons: (1) hypersomnia not of central origin, (2) untreated moderate to severe sleep-related breathing disorder (AHI ≥ 15), (3) uncontrolled psychiatric or medical condition that would interfere with the ability to participate in the study, (4) current suicidal ideation or intent, (5) previous participation in a formal MBI program (e.g. Mindfulness-Based Stress Reduction; MBSR), and (6) unstable narcolepsy medications.

Recruitment employed a variety of strategies, including email/social media announcements from nonprofit hypersomnia organizations, social media advertisements, word of mouth, fliers displayed at local clinics, and presentations at national conferences for hypersomnia patients and sleep medicine professionals. All study procedures were performed remotely via telephone and videoconference. Study data were collected and managed using REDCap (Research Electronic Data Capture) tools hosted at Northwestern University [20, 21]. REDCap is a secure, web-based software platform designed to support data capture for research studies.

Initial screening procedures involved a survey to determine possible eligibility based on age, place of residence, self-reported diagnosis, previous mindfulness experience, PROMIS depression, and PROMIS anxiety. Based on initial screening, eligible individuals were invited to complete a screening interview which collected medical and psychiatric history as well as current medications. Individuals were also asked to provide medical documentation (e.g. office visit note and sleep study report) showing their narcolepsy diagnosis. Eligible individuals who enrolled in the study completed a baseline assessment consisting of questionnaires, neurocognitive testing, and one week of actigraphy (devices were mailed to participants). Following this, participants were randomly assigned to receive one of three versions of an MBI for narcolepsy: 4-week program (brief MBI), 8-week program (standard MBI), or 12-week program (extended MBI). Baseline questionnaires were re-administered at 4, 8, and 12 weeks. Neurocognitive testing and actigraphy were repeated at the posttreatment assessment only (i.e. the assessment immediately following completion of the intervention: at 4 weeks for the brief MBI group, at 8 weeks for the standard MBI group, and at 12 weeks for the extended MBI group; actigraphy data are not presented in this paper). Study procedures were approved by the Institutional Review Board at Northwestern University and all participants provided informed consent.

Intervention

All study intervention arms were modeled after the content and structure of MBSR [22] and delivered by trained mindfulness instructors to small groups (n = 4 in each group) via synchronous videoconference. In each session, the instructor provided didactic instruction, facilitated discussion, and led participants in mindfulness practices including body scan meditation, sitting meditation, walking meditation, and yoga. MBSR is typically delivered as an 8-week program, and the primary aim of this study was to test the feasibility of a standard 8-week program compared to two modified versions. The brief MBI was developed to optimize cost-effectiveness and minimize patient impacts by using a more concentrated version of the core mindfulness principles (8 hours of contact). The standard MBI was used to compare a typical dose of MBI (16 hours of contact) that contains the typical components of an MBSR program with minor modifications to enhance relevance for managing narcolepsy symptoms. Finally, the extended MBI was designed to optimize acceptability by using a more gradual pace of learning and offering participants the option to have additional one-on-one instruction (16 hours of contact plus up to two optional hours of individual instruction). In the brief and standard groups, participants met once a week for 4 and 8 weeks, respectively. The extended (12-week) program attended weekly group sessions for the first 4 weeks of the intervention, but these group meetings occurred every other week for the last 8 weeks of treatment. On the weeks that meetings did not occur, participants in this group had the option to attend a half-hour individual session with the instructor, who was available to answer questions and help participants troubleshoot their mindfulness practice (Table 1).

Table 1.

Mindfulness-Based Intervention Session Timeline and Topics

Group	Week
	1	2	3	4	5	6	7	8	9	10	11	12
Brief MBI	Sab	Sc	Se	Sg		R
Standard MBI	Sa	Sb	Sc	Sd	Se	Sf,R	Sg	Sh
Extended MBI	Sa	Sb	Sc	Sd	O	Se,R	O	Sf	O	Sg	O	Sh

MBI, mindfulness-based intervention; S, session (group); R, retreat; O, office hours (individual instruction and troubleshooting). Superscript letters denote session topics.

^aIntroduction and overview.

^bMindful awareness and de-centering.

^cSelf-compassion.

^dManaging energy with mindfulness and self-compassion.

^eActive acceptance.

^fTaking mindful action: responding versus reacting.

^gValue-congruent living with narcolepsy.

^hMindful living with narcolepsy.

For all versions of the intervention, modifications to standard MBSR were made to tailor the intervention for narcolepsy with the intent of enhancing acceptability. To account for difficulty sustaining alertness and attention over long periods, sessions were shortened (2 hours rather than 2.5 hours) and the meditation retreat was 2 hours rather than a full day (for the retreat, participants from all three concurrent groups joined together to engage in silent mindfulness practices). In addition, discussions of mindfulness principles focused on the application to narcolepsy, for example, (1) using mindful awareness of physical and mental states to regulate emotion and energy, (2) cultivation of self-compassion and mindful action to enhance self-identity and self-image, (3) using active acceptance to embrace and actively manage the symptoms of narcolepsy, and (4) maintaining value-congruent living to enhance self-efficacy for living with narcolepsy. Between sessions, participants were encouraged to meditate for 30 to 45 minutes per day and record their practice on a paper meditation log. Resources for home practice, such as guided audio recordings, were distributed via email. Video recordings of the sessions were made available to participants who needed to make up any session they had missed.

Instructor training.

Five mindfulness instructors with no previous experience with narcolepsy were recruited to provide the intervention. All instructors were experienced in providing MBI and four were licensed health professionals (two doctoral-level and two masters-level providers). Each instructor was provided 10 hours of study-specific training that included an overview of narcolepsy, considerations for working with PWN, and the treatment manual for all three MBI conditions. Instructors also attended group meetings between each treatment cohort to review progress and discuss challenges and issues.

Measures

Acceptability and feasibility.

Data on treatment acceptability were collected to assess patient-centered factors related to the delivery and contents of the MBI programs. Acceptability was assessed qualitatively through exit interviews and quantitatively through attendance, home meditation practice, and by assessing treatment credibility. Exit interviews queried the acceptability of the format, content, and delivery of the intervention along with a rating of the likelihood of referring the MBI program to another PWN on a scale of 1 (“very unlikely to refer”) to 5 (“very likely to refer”). For session attendance, a prespecified benchmark of attending ≥ 80% of sessions indicated acceptable participant engagement. To meet this benchmark, a participant needed to attend all four sessions for brief MBI, ≥ 7 sessions (out of eight) for standard MBI, and ≥10 sessions (out of 12) for extended MBI. For home meditation practice, a prespecified benchmark of practicing ≥4 days per week indicated acceptable adherence. Participants recorded their meditation practice on logs throughout the duration of treatment, noting each day both the number of practice sessions and type of practice (sitting meditation, body scan, yoga, walking meditation, and informal practice) in which they engaged. In addition to these benchmarks, treatment credibility was assessed using a four-item treatment credibility and expectancy questionnaire [23], completed after the first intervention session. Three items for that measure provided a score range of 1 to 9, with higher scores indicating better credibility and expectancy. The fourth item asked participants to indicate how much improvement in quality of life they expected from the treatment, from 0% to 100%.

Feasibility was assessed by tracking the enrollment rate and the completeness of study data. For enrollment, a prespecified goal of ≥ 4 participants per month was used to demonstrate the feasibility of recruiting and enrolling an adequate number of PWN to conduct future clinical trials. For data completeness, a prespecified goal of obtaining complete data (baseline and posttreatment) from at least 80% of participants was used to demonstrate the feasibility of remote data collection methods.

Mindfulness and self-compassion.

Participants completed the Five Facet Mindfulness Questionnaire (FFMQ) [24] to measure the acquisition of mindfulness skills. The facets measured by the FFMQ include non-reactivity to inner experience, observing, acting with awareness, describing, and nonjudging of experience. The Self-Compassion Scale (SCS) [25] was administered to assess self-compassion along three dimensions: self-kindness versus self-judgment, common humanity versus isolation, and mindfulness versus over-identification. These measures assess the acquisition of mindfulness principles and self-compassion, the putative psychological mechanism of MBI. Higher scores on these measures indicate higher levels of mindfulness and self-compassion, respectively.

Psychosocial functioning and symptom impacts.

To assess the impact of the intervention on mood and psychosocial functioning, participants completed the following PROMIS (PROMIS) measures: Depression [19], Anxiety [19], General Self-Efficacy [26], Self-Efficacy for Managing Chronic Conditions [27], Social Isolation [28], Ability to Participate in Social Roles and Activities [28], and Psychosocial Illness Impact [29]. In addition, the following PROMIS measures were administered to assess sleep- and health-related symptoms: Sleep Disturbance [30], Sleep-Related Impairment [30], Fatigue [31], Global Health [32], and Cognitive Function [33]. Fixed-length short forms were used for Global Health and Psychosocial Illness Impact, and all other PROMIS measures employed the computer adaptive test form. Each of the PROMIS measures yields a T-score that is used to assess the strength of the variable, with a mean of 50 corresponding to the average level relative to the normative sample and a standard deviation of 10. Across PROMIS measures, higher scores indicate more of the construct being assessed. Therefore, higher scores can indicate either better or worse functioning depending upon the measure in question (e.g. a higher score on the PROMIS Depression measure indicates more depressive symptoms, a higher score on the PROMIS Self-Efficacy measure indicates greater self-efficacy). PROMIS measures have specifically been recommended for symptom assessment in mindfulness-based intervention studies [34].

Additional measures were completed to assess sleep- and narcolepsy-related symptoms, including daytime sleepiness (Epworth Sleepiness Scale [35]), hypersomnia symptoms (Hypersomnia Severity Index [36]), and the impact of hypersomnia on daytime functioning (Functional Outcomes of Sleep Questionnaire [37]).

Neurocognitive.

The following measures were administered via videoconference at baseline and posttreatment (with applicable materials mailed to participants): Trail Making Test [38] (visual scanning, visual motor speed, sequencing, and set-shifting); Repeatable Battery for the Assessment of Neuropsychological Status [39] (RBANS; immediate memory, visuospatial/constructional, language, attention, delayed memory), Stroop Color and Word Test [40] (processing speed, dual attention, inhibition, and executive function), Neuropsychological Assessment Battery (NAB) Digits Forward/Digits Backward Test [41] (working memory), and Controlled Oral Word Association Test [42] (COWAT; phonemic fluency). To minimize practice effects, different forms of these measures were used at posttreatment for RBANS and NAB.

Data analysis

The data analytic approach reflects the recommendations for feasibility trials [43] by focusing on prespecified benchmarks, indications of treatment effects, and emerging themes from qualitative data rather than formal hypothesis testing. To evaluate the feasibility and acceptability of telehealth-delivered MBI for PWN, we used the prespecified benchmarks described above (see acceptability and feasibility) to evaluate participant enrollment, participant engagement, and completeness of study data. For qualitative data, we examined the responses from the exit interview for emerging patterns and themes across participants and collated the responses into common themes. To evaluate the clinical impact of the three versions of MBI, we used an effect size of Cohen’s d ≥ 0.5 as the prespecified benchmark for a minimal clinically important difference (MCID) on patient-reported outcome measures and neurocognitive assessments. To complement these benchmarks, we report p values using paired samples t-tests of baseline-to-posttreatment changes for each treatment group as well as the entire sample. Quantitative data analyses were conducted using an intent-to-treat approach on all participants who were allocated to treatment (N = 60), with the last observation carried forward for participants for whom posttreatment data were not available.

Results

Enrollment, participant characteristics, and data completeness

As shown in Figure 1, 206 individuals were screened for the study and 60 participants were randomized. The recruitment period duration was 20 months (May 2020 to December 2021), during which time 84 individuals were consented to the study, resulting in an average enrollment of 4.2 participants per month, exceeding the enrollment benchmark (≥4 participants per month). Participant characteristics are in Table 2. Of the 60 randomized participants, 26 (43.3%) had a diagnosis of NT1 and 34 (56.7%) had a diagnosis of NT2. Participants had a mean age of 35.6 and included 53 women, 5 men, and 2 non-binary individuals. Participants reported their race as white (n = 56), Asian or Asian-American (n = 4), and black or African American (n = 1), and 10% identified as Hispanic/Latino.

Figure 1.

CONSORT flow diagram. Brief MBI = 4-week mindfulness-based intervention (MBI). Standard = 8-week MBI. Extended = 12-week MBI.

Table 2.

Participant Diagnoses and Demographic Characteristics

Characteristic	n	%
Diagnosis
Narcolepsy type 1	26	43.3%
Narcolepsy type 2	34	56.7%
Gender
Female	53	88.3%
Male	5	8.3%
Non-binary	2	3.3%
Race
White	56	93.3%
Asian or Asian-American	4	6.7%
Black or African-American	1	1.7%
Ethnicity
Not Hispanic/Latino	54	90.0%
Hispanic/Latino	6	10.0%
Relationship status
Single	30	50.0%
Married	21	35.0%
Cohabiting	5	8.3%
Divorced	4	6.7%
	M	SD
Age (years)	35.6	12.2
Education (years)	16.0	2.7
Time since diagnosis (years)	6.0	6.5

Only the brief and extended groups met the prespecified benchmark of obtaining complete baseline and posttreatment assessments for at least 80% of participants. Across groups, the rate of missing or incomplete questionnaires was 5.83% (7 out of 120 possible administrations [baseline and posttreatment assessments for 60 participants]). The rate of missing neurocognitive testing was 10.83% (13 out of 120).

Treatment acceptability

For attendance at treatment sessions, 71.7% of participants across groups met the benchmark (≥80% of sessions). Table 3 shows the percentage of each group who met this benchmark. Four participants (two each in the brief/extended groups) who missed a session were allowed to watch a recorded video of the session. Since this demonstrates engagement but was not included in the original benchmark, we also report data including those who met the benchmark by watching the recording. For meditation practice, 61.7% of participants met the benchmark of practicing ≥4 days per week, with 80% of brief MBI, 40% of standard MBI, and 65% of extended MBI reaching the benchmark. The overall mean number of meditation sessions (Table 4) was 12.97 per week (SD = 8.10) and the overall mean duration of meditation practice was 178.06 minutes per week (SD = 94.82 minutes).

Table 3.

Number and Percentage of Participants Meeting Feasibility and Acceptability Benchmarks

Benchmark	Brief MBI (n = 20)		Standard MBI (n = 20)		Extended MBI (n = 20)		Total (N = 60)
	n	%	n	%	n	%	N	%
Attendance at ≥80% sessions	15	75.0%	13	65.0%	15	75.0%	43	71.7%
Attendance or video ≥80% sessions*	17	85.0%	13	65.0%	17	85.0%	47	78.3%
Meditation practice ≥4 days per week	16	80.0%	8	40.0%	13	65.0%	37	61.7%
Complete assessment data	18	90.0%	13	65.0%	16	80.0%	47	78.3%

^*This modified benchmark includes individuals who made up a missed session by watching at least 50% of the recording.

MBI, mindfulness-based intervention.

Table 4.

Meditation Practice

Meditation practice	M (SD)
Meditation type	Brief MBI	Standard MBI	Extended MBI	Total
Frequency (sessions/week)
Body scan/sitting	7.49 (6.06)	6.40 (5.11)	7.88 (6.83)	7.27 (5.98)
Movement	3.62 (2.55)	3.22 (2.29)	2.27 (2.64)	3.03 (2.53)
Informal	3.08 (2.82)	2.33 (3.77)	3.02 (2.09)	2.82 (2.92)
Total	14.18 (7.50)	11.65 (9.09)	13.01 (7.94)	12.97 (8.10)
Duration (minutes/week)
Body scan/sitting	84.37 (51.14)	80.23 (57.99)	96.48 (60.50)	87.10 (55.97)
Movement	73.34 (64.55)	70.52 (60.30)	30.57 (27.70)	57.97 (56.05)
Informal	35.88 (33.10)	32.53 (64.73)	37.09 (26.18)	35.24 (42.97)
Total	193.58 (85.61)	177.56 (126.67)	162.19 (67.42)	178.06 (94.82)

MBI, mindfulness-based intervention; Movement, yoga or walking meditation; Informal, mindfulness during everyday activities.

Meditation diaries were collected for 4 weeks for Brief MBI, 8 weeks for Standard MBI, and 12 weeks for Extended MBI.

For treatment credibility (Table 5), participants rated the MBI programs as logical (overall mean = 7.45, SD = 1.49) with moderate success (M = 5.16, SD = 1.78), moderate confidence in recommending the program (M = 6.09, SD = 1.98), and moderate expectations for improvement (M = 51.41, SD = 26.10). At the end of the study, participants reported a high likelihood they would refer other PWN to the program, with a mean rating of 4.49 out of 5 (SD = .95).

Table 5.

Treatment Credibility and Expectancy Ratings

Item	M (SD)
	Brief MBI	Standard MBI	Extended MBI	Total
At this point, how logical does this mindfulness program seem? (1 = Not at all logical, 9 = Very logical)	7.35 (1.73)	7.63 (1.12)	7.37 (1.61)	7.45 (1.49)
At this point, how successful do you think this mindfulness program will be in reducing your sleep problems? (1 = Not at all successful, 9 = Very successful)	4.90 (2.05)	5.63 (1.77)	4.95 (1.43)	5.16 (1.78)
How confident would you be in recommending this mindfulness program to a friend who experiences similar sleep problems? (1 = Not at all confident, 9 = Very confident)	5.70 (2.23)	6.74 (1.79)	5.84 (1.83)	6.09 (1.98)
By the end of this phase of therapy, how much improvement in your quality of life do you think will occur because of this approach? (0%–100%)	49.15 (28.44)	53.89 (24.60)	51.32 (26.20)	51.41 (26.10)

MBI, mindfulness-based intervention.

Qualitative data from exit interviews revealed that participants generally felt positive about using videoconferencing to participate in the intervention. Although occasional connectivity problems were a downside, participants noted that benefits included getting to meet other PWN from across the country, increased intervention accessibility due to not needing to travel, and increased comfort from being in their home setting. To enhance the latter, some participants would have liked more information in advance about the setup required for certain exercises (e.g. having enough room to move around for yoga or walking meditation). Regarding the group format, participants spoke enthusiastically about the benefits of being in a group with other PWN. For example, one participant (extended MBI) stated, “It was very powerful to connect with three other people who have narcolepsy, especially all across the United States. I would get emotional with just how powerful it is to have contact with people that are going through the same kind of rare thing that you are.” Similarly, another participant (brief MBI) remarked, “For me it was very valuable to connect with other PWN. I had met people through support groups, but this was a bit more intimate.”

Most participants expressed that the 2-hour length of the sessions was appropriate, although some recommended shortening the sessions because of difficulties with scheduling or with sustaining attention/alertness. Regarding the number of weeks of the MBI, many of the brief group participants expressed dissatisfaction with the limited number of sessions. The standard group overall was satisfied with the length, though some were open to more sessions. No participants in the extended group desired a longer MBI and two felt it was too long.

Regarding the content of the MBI, participants endorsed varying preferences for particular types of meditation, and difficulty staying awake was noted particularly with the body scan. Participants also provided feedback that they would have liked for the MBI to have been more tailored to narcolepsy. Specifically, they felt discussion of narcolepsy—as well as how to apply mindfulness to narcolepsy—was too limited. As described by one participant (brief MBI), “I just felt like there was something missing. We did the mindfulness, but not the stepping stone to relating it to narcolepsy.” Participants suggested greater depth and specificity in tying mindfulness to narcolepsy, including discussing specific symptoms such as cataplexy, hallucinations, and brain fog.

Psychosocial functioning and symptom impacts

Table 6 summarizes group means at baseline and posttreatment for each of the questionnaires along with effect size (Cohen’s d) and p values (group means at each of the four assessments are displayed in Supplementary Table 1). Figure 2 displays the effect sizes for changes in these outcomes from baseline to posttreatment. All three MBI versions met the MCID (Cohen’s d ≥ 0.5) on the FFMQ and SCS with medium to large effect sizes. On PROMIS measures, extended MBI met the MCID on anxiety, depression, all self-efficacy domains, all social domains, cognitive functioning, psychosocial illness impact (positive and negative), global mental health, and fatigue. Extended MBI also met the MCID on the ESS, HSI, and FOSQ. Standard MBI met the MCID on anxiety, all self-efficacy domains except managing social interactions, psychosocial illness impact (positive), global mental health, sleep-related impairment, and fatigue. Brief MBI met the MCID on PROMIS measures for self-efficacy for managing emotions, positive psychosocial impact, global mental health, sleep-related impairment, and fatigue. None of the groups met the MCID on PROMIS global physical health or sleep disturbance. In the exit interviews, participants described numerous ways in which they perceived the MBI had improved narcolepsy symptoms or aspects of psychosocial functioning. These qualitative data are summarized in Table 7.

Table 6.

Mindfulness and Clinical Outcomes at Baseline and Posttreatment

Measure	M (SD)		t	P	d *
	Baseline	Posttreatment
Five Facet Mindfulness Questionnaire
Brief MBI	115.90 (24.80)	132.00 (21.40)	−3.65	.002	0.82
Standard MBI	122.50 (22.13)	143.95 (15.26)	−4.02	.001	0.90
Extended MBI	107.00 (13.43)	134.30 (19.59)	−7.69	.000	1.72
Total	115.13 (21.33)	136.75 (19.32)	−8.26	.000	1.07
Self-Compassion Scale
Brief MBI	2.66 (0.80)	3.09 (0.85)	−2.62	.017	0.59
Standard MBI	2.91 (0.82)	3.59 (0.55)	−4.13	.001	0.92
Extended MBI	2.52 (0.50)	3.51 (0.61)	−6.88	.000	1.54
Total	2.70 (0.72)	3.40 (0.70)	−7.42	.000	0.96
PROMIS Anxiety
Brief MBI	62.54 (7.04)	62.51 (9.53)	0.02	.986	0.00
Standard MBI	61.24 (4.85)	56.92 (6.01)	2.49	.022	−0.56
Extended MBI	61.69 (6.67)	58.03 (7.34)	2.72	.014	−0.61
Total	61.82 (6.18)	59.15 (8.01)	2.84	.006	−0.37
PROMIS Depression
Brief MBI	59.53 (4.76)	57.69 (8.84)	1.14	.270	−0.25
Standard MBI	56.11 (4.81)	54.33 (6.10)	1.50	.151	−0.33
Extended MBI	60.06 (6.25)	53.25 (6.30)	5.68	.000	−1.27
Total	58.57 (5.52)	55.09 (7.32)	4.21	.000	−0.54
PROMIS General Self-Efficacy
Brief MBI	43.20 (8.49)	45.32 (9.38)	−1.47	.157	0.33
Standard MBI	44.57 (8.01)	49.00 (8.11)	−2.27	.035	0.51
Extended MBI	41.16 (7.93)	46.33 (9.56)	−3.55	.002	0.79
Total	42.98 (8.13)	46.88 (9.02)	−4.15	.000	0.54
PROMIS Self-Efficacy for Managing Symptoms
Brief MBI	40.90 (5.02)	42.62 (7.11)	−0.94	.359	0.21
Standard MBI	41.43 (4.18)	46.42 (7.93)	−3.00	.007	0.67
Extended MBI	39.43 (4.58)	43.79 (5.20)	−3.94	.001	0.88
Total	40.58 (4.61)	44.27 (6.91)	−4.07	.000	0.53
PROMIS Self-Efficacy for Managing Emotions
Brief MBI	42.12 (7.02)	44.77 (6.76)	−2.22	.039	0.50
Standard MBI	43.51 (6.38)	48.71 (4.14)	−3.28	.004	0.73
Extended MBI	39.43 (4.59)	45.78 (6.95)	−5.08	.000	1.14
Total	41.68 (6.22)	46.42 (6.21)	−5.96	.000	0.77
PROMIS Self-Efficacy for Managing Social Interactions
Brief MBI	44.48 (4.87)	45.28 (7.74)	−0.78	.446	0.17
Standard MBI	42.93 (6.55)	46.21 (6.76)	−1.83	.083	0.41
Extended MBI	42.07 (4.42)	45.91 (5.31)	−5.07	.000	1.13
Total	43.16 (5.36)	45.80 (6.58)	−3.56	.001	0.46
PROMIS Ability to Participate in Social Roles and Activities
Brief MBI	42.56 (5.64)	42.04 (5.52)	0.33	.748	−0.07
Standard MBI	41.93 (5.05)	42.81 (5.04)	−0.65	.521	0.15
Extended MBI	39.55 (9.39)	42.53 (7.52)	−2.37	.028	0.53
Total	41.34 (6.97)	42.46 (6.03)	−1.36	.179	0.18
PROMIS Social Isolation
Brief MBI	56.63 (6.13)	54.32 (9.19)	1.69	.108	−0.38
Standard MBI	56.18 (7.12)	53.49 (6.51)	1.57	.132	−0.35
Extended MBI	59.97 (6.16)	55.33 (9.28)	2.73	.013	−0.61
Total	57.59 (6.60)	54.38 (8.32)	3.50	.001	−0.45
PROMIS Cognitive Function
Brief MBI	40.54 (5.51)	40.93 (6.92)	−0.27	.792	0.06
Standard MBI	39.98 (6.37)	41.79 (5.90)	−1.38	.184	0.31
Extended MBI	37.95 (4.68)	42.07 (5.45)	−2.84	.011	0.63
Total	39.49 (5.58)	41.60 (6.04)	−2.56	.013	0.33
PROMIS Psychosocial Illness Impact—Negative
Brief MBI	60.94 (6.53)	58.46 (9.88)	1.64	.118	−0.37
Standard MBI	59.35 (5.28)	56.90 (6.11)	2.01	.058	−0.45
Extended MBI	62.59 (8.26)	57.73 (6.42)	4.33	.000	−0.97
Total	60.96 (6.82)	57.69 (7.56)	4.35	.000	−0.56
PROMIS Psychosocial Illness Impact—Positive
Brief MBI	39.35 (8.00)	41.89 (9.65)	−2.24	.037	0.50
Standard MBI	42.07 (6.84)	46.02 (8.49)	−2.35	.030	0.52
Extended MBI	38.74 (7.23)	43.04 (8.55)	−3.89	.001	0.87
Total	40.05 (7.39)	43.65 (8.93)	−4.71	.000	0.61
PROMIS Global Mental Health
Brief MBI	38.01 (7.89)	41.46 (9.90)	−2.40	.027	0.54
Standard MBI	40.43 (6.07)	45.18 (7.52)	−2.75	.013	0.61
Extended MBI	36.03 (7.82)	41.27 (8.68)	−4.06	.001	0.91
Total	38.15 (7.41)	42.63 (8.80)	−5.24	.000	0.68
PROMIS Global Physical Health
Brief MBI	46.32 (7.46)	47.20 (8.00)	−0.64	.530	0.14
Standard MBI	43.85 (6.15)	45.52 (6.92)	−1.37	.187	0.31
Extended MBI	43.71 (6.44)	44.74 (7.73)	−1.26	.221	0.28
Total	44.62 (6.70)	45.82 (7.51)	−1.81	.076	0.23
PROMIS Sleep Disturbance
Brief MBI	55.76 (4.39)	54.58 (4.77)	1.38	.183	−0.31
Standard MBI	54.91 (7.34)	50.91 (9.50)	2.20	.040	−0.49
Extended MBI	54.87 (7.44)	52.39 (7.77)	1.59	.128	−0.36
Total	55.18 (6.45)	52.63 (7.63)	3.02	.004	−0.39
PROMIS Sleep-Related Impairment
Brief MBI	65.48 (6.40)	62.99 (7.41)	2.22	.039	−0.50
Standard MBI	64.63 (7.64)	60.51 (8.68)	3.09	.006	−0.69
Extended MBI	64.56 (6.42)	61.52 (10.15)	2.09	.050	−0.47
Total	64.89 (6.74)	61.67 (8.73)	4.30	.000	−0.55
PROMIS Fatigue
Brief MBI	66.55 (6.59)	63.86 (8.21)	2.30	.033	−0.51
Standard MBI	65.31 (4.26)	61.01 (7.72)	2.96	.008	−0.66
Extended MBI	67.40 (6.51)	62.73 (9.42)	2.98	.008	−0.67
Total	66.42 (5.85)	62.53 (8.42)	4.82	.000	−0.62
Epworth Sleepiness Scale
Brief MBI	13.40 (4.16)	12.65 (4.74)	1.18	.253	−0.26
Standard MBI	12.15 (5.35)	11.85 (5.42)	0.47	.641	−0.11
Extended MBI	14.05 (5.19)	11.30 (5.26)	4.00	.001	−0.89
Total	13.20 (4.91)	11.93 (5.09)	3.20	.002	−0.41
Hypersomnia Severity Index
Brief MBI	20.65 (4.75)	18.15 (7.65)	2.06	.053	−0.46
Standard MBI	18.85 (6.12)	16.80 (6.83)	2.05	.055	−0.46
Extended MBI	21.25 (5.90)	18.20 (7.98)	3.05	.007	−0.68
Total	20.25 (5.62)	17.72 (7.41)	4.13	.000	−0.53
Functional Outcomes of Sleep Questionnaire
Brief MBI	13.34 (2.91)	14.02 (3.06)	−1.34	.195	0.30
Standard MBI	13.90 (2.66)	14.08 (3.32)	−0.31	.757	0.07
Extended MBI	12.13 (3.36)	13.66 (3.51)	−3.21	.005	0.72
Total	13.12 (3.03)	13.92 (3.25)	−2.59	.012	0.33

^*Positive effect sizes indicate an increase in the construct being measured, and negative effect sizes indicate a decrease. For Functional Outcomes of Sleep Questionnaire, an increase indicates improvement in function.

MBI, mindfulness-based intervention; PROMIS, Patient-Reported Outcomes Measurement Information System.

N = 60 for total sample, n = 20 for each treatment group. Posttreatment was at 4 weeks for Brief MBI, 8 weeks for Standard MBI, and 12 weeks for Extended MBI.

Figure 2.

Within-group and total sample effect sizes for changes in mindfulness and clinical outcomes from baseline to posttreatment. Brief = 4-week Mindfulness-based intervention (MBI). Standard = 8-week MBI. Extended = 12-week MBI. FFMQ, Five Facet Mindfulness Questionnaire; SCS, Self-Compassion Scale; Anx = Patient-Reported Outcomes Measurement Information System (PROMIS) Anxiety. Dep = PROMIS Depression. GSE = PROMIS General Self-Efficacy. SEM Sx = PROMIS Self-Efficacy for Managing Symptoms. SEM Emot = PROMIS Self-Efficacy for Managing Emotions. SEM Soc = PROMIS Self-Efficacy for Managing Social Interactions. Partic Soc = PROMIS Ability to Participate in Social Roles and Activities. Isol = PROMIS Social Isolation. Cog Func = PROMIS Cognitive Function. Impact Neg = PROMIS Psychosocial Illness Impact—Negative. Impact Pos = PROMIS Psychosocial Illness Impact—Positive. Global Mental = PROMIS Global Mental Health. Global Physical = PROMIS Global Physical Health. Sleep Disturb = PROMIS Sleep Disturbance. Sleep Impair = PROMIS Sleep-Related Impairment. Fatigue = PROMIS Fatigue. ESS, Epworth Sleepiness Scale; HSI, Hypersomnia Severity Index; FOSQ, Functional Outcomes of Sleep Questionnaire.

Table 7.

Impact of Mindfulness-Based Intervention on Narcolepsy Symptoms and Psychosocial Functioning

Symptom domain	Example quotes from exit interviews
Daytime sleepiness	“Deep breathing exercises do a lot to wake me up when sleep attacks are coming on.” “The transition time between sleeping and waking has become significantly shorter—not less painful, but definitely shorter.” “My sleep attacks were getting lighter, shorter, and further apart.” “I don’t think it has changed my awakeness, but I am less critical of myself for sleeping and taking naps.” “I’m not sure if it actually helped with sleepiness, but it did help me be more aware of when I feel tired, and giving myself compassion about it instead of being upset about it.” “It helped me tune into my body more to anticipate sleepiness, and I was able to look at myself with compassion.”
Cataplexy	“My cataplexy is unchanged, but loving kindness with cataplexy has been helpful.” “Normally I can’t really control my cataplexy attacks, but recently I use the breathing techniques and I can stop it. When it kind of starts I will switch to breathing and kind of stop it.”
Sleep paralysis and hallucinations	“Whenever I have sleep paralysis or hallucinations, I am working on being more mindful in my subconscious realities. During the in-between it can be difficult so I use a breathing exercise to reconnect to my body so I know that I am out of the hallucination and I don’t know if I’m in a dream state or not. Breathing activities helps me to reclaim my autonomy.”
Nocturnal sleep disturbance	“Body scans really help me when I fall asleep at night.” “I feel like it was very helpful for my anxiety, especially at night when I get a lot of insomnia and I’m trying to get back to sleep. I get anxiety because I can’t get back to sleep, but meditating helps me stay calm.” “With narcolepsy, a lot of times you deal with insomnia. Learning some different meditations and mindfulness activities has been really helpful with getting to sleep.”
Anxiety	“It really helped me to manage my anxiety.” “I found that it’s more helpful with my anxiety than it is with narcolepsy.”
Depression	“It has helped with my depression because instead of beating myself up for having narcolepsy, I’ll say, ‘It’s okay. I have narcolepsy. It’s not my fault.’…a lot of things are out of my control with narcolepsy, so with meditating, I’ve realized that and it’s helped my depression.” “It was very beneficial for my mental health. I can see how it will definitely help me with feelings of depression and some of the negative feelings that go along with having narcolepsy.”
Stigma	“I liked the breathing meditation and compassion meditation because I feel like I’m hard on myself a lot. People with narcolepsy tend to be hard on themselves a lot. It comes with the stigma people give us. So trying to be compassionate towards myself and doing the meditation has been very helpful.”

Although this trial was not designed to test differences in treatment effects based on diagnosis, we examined on an exploratory basis how each diagnostic group changed from baseline to posttreatment. Group means at baseline and posttreatment are shown in Supplementary Table 2, and  Figure 1 displays effect sizes for these changes. The general pattern did not differ between NT1 and NT2 on whether they met the MCID, with the exception of four measures on which NT2 met the MCID and NT1 did not (self-efficacy for managing symptoms, self-efficacy for managing social interactions, negative illness impact, Hypersomnia Severity Index).

Neurocognitive measures

Table 8 summarizes group means at baseline and posttreatment for each of the measures along with effect size (Cohen’s d) and p values. Figure 3 displays the effect sizes for changes in these outcomes from baseline to posttreatment. Brief MBI met the MCID for the RBANS Immediate Memory Index, RBANS Attention Index, and Stroop Color-Word. Standard MBI did not meet the MCID for any measures, and extended MBI met the MCID for Stroop Color-Word. Across groups, the most common and consistent improvement was dependent on inhibition (Stroop Color-Word), though standard MBI fell short of the MCID. Brief MBI showed relatively distinct (compared to standard and extended MBI) improvements in ability to immediately repeat verbal stimuli and cognitive throughput (RBANS Immediate Memory Index and Attention Index).

Table 8.

Neurocognitive Outcomes at Baseline and Posttreatment

Measure	n	M (SD)		t	P	d*
		Baseline	Posttreatment
Trail Making A (raw score)
Brief MBI	20	23.60 (6.72)	21.45 (6.75)	1.64	.117	0.37
Standard MBI	20	33.93 (15.69)	27.71 (8.63)	2.21	.039	0.49
Extended MBI	20	27.31 (9.47)	27.01 (8.37)	0.21	.837	0.05
Total	60	28.28 (11.89)	25.39 (8.32)	2.48	.016	0.32
Trail Making B (raw score)
Brief MBI	20	53.63 (27.79)	51.20 (34.83)	0.47	.643	0.11
Standard MBI	20	71.09 (25.33)	59.97 (20.83)	1.97	.064	0.44
Extended MBI	20	62.60 (29.91)	57.59 (16.31)	0.70	.494	0.16
Total	60	62.44 (28.20)	56.25 (25.10)	1.78	.080	0.23
RBANS Immediate Memory Index
Brief MBI	20	93.95 (15.53)	102.25 (14.71)	−2.41	.026	0.54
Standard MBI	20	100.80 (12.97)	103.75 (13.87)	−1.39	.180	0.31
Extended MBI	20	93.65 (15.07)	96.45 (13.78)	−1.48	.156	0.33
Total	60	96.13 (14.70)	100.82 (14.24)	−3.12	.003	0.40
RBANS Visuospatial/Constructional Index
Brief MBI	20	94.25 (15.04)	88.70 (13.74)	1.62	.122	−0.36
Standard MBI	20	97.80 (14.11)	101.00 (16.08)	−1.24	.230	0.28
Extended MBI	19	99.47 (12.79)	94.68 (13.23)	1.62	.124	−0.37
Total	59	97.14 (13.96)	94.80 (15.06)	1.31	.196	−0.17
RBANS Language Index
Brief MBI	20	107.10 (13.32)	107.35 (14.48)	−0.09	.929	0.02
Standard MBI	20	107.20 (9.26)	104.20 (13.72)	1.13	.271	−0.25
Extended MBI	20	101.00 (15.98)	99.10 (12.78)	0.78	.444	−0.17
Total	60	105.10 (13.25)	103.55 (13.87)	1.03	.306	−0.13
RBANS Attention Index
Brief MBI	20	97.90 (19.25)	106.00 (19.08)	−3.10	.006	0.69
Standard MBI	19	97.16 (16.09)	98.63 (14.62)	−0.66	.518	0.15
Extended MBI	19	100.79 (14.29)	100.68 (16.72)	0.04	.972	−0.01
Total	58	98.60 (16.50)	101.84 (16.94)	−2.07	.043	0.27
RBANS Delayed Memory Index
Brief MBI	20	98.00 (15.88)	96.05 (14.49)	1.02	.321	−0.23
Standard MBI	19	100.00 (9.74)	104.58 (9.91)	−1.96	.066	0.45
Extended MBI	19	96.95 (12.10)	98.89 (7.06)	−1.11	.283	0.25
Total	58	98.31 (12.72)	99.78 (11.38)	−1.22	.226	0.16
RBANS Total Scale Index
Brief MBI	20	97.65 (16.27)	100.15 (16.59)	−1.25	.226	0.28
Standard MBI	19	101.26 (10.62)	103.47 (13.46)	−1.12	.278	0.26
Extended MBI	19	97.89 (11.99)	96.79 (10.76)	0.68	.502	−0.16
Total	58	98.91 (13.12)	100.14 (13.89)	−1.13	.264	0.15
Stroop word (T-score)
Brief MBI	20	43.15 (14.31)	46.10 (14.01)	−2.13	.046	0.48
Standard MBI	20	35.20 (11.79)	35.60 (12.4)	−0.34	.739	0.08
Extended MBI	20	43.30 (11.12)	44.10 (13.78)	−0.68	.503	0.15
Total	60	40.55 (12.85)	41.93 (13.97)	−1.91	.061	0.25
Stroop color (T-score)
Brief MBI	20	46.2 (12.14)	47.90 (11.92)	−1.28	.217	0.29
Standard MBI	20	40.45 (9.11)	42.15 (11.24)	−1.24	.229	0.28
Extended MBI	20	46.85 (8.75)	47.05 (10.25)	−0.16	.873	0.04
Total	60	44.50 (10.36)	45.70 (11.26)	−1.60	.115	0.21
Stroop color-word (T-score)
Brief MBI	20	54.75 (11.25)	57.90 (11.37)	−2.23	.038	0.50
Standard MBI	20	49.85 (9.91)	52.30 (11.27)	−1.82	.084	0.41
Extended MBI	20	53.75 (8.28)	56.75 (8.81)	−2.40	.027	0.54
Total	60	52.78 (9.95)	55.65 (10.65)	−3.78	.000	0.49
NAB digits forward (raw score)
Brief MBI	20	9.80 (2.21)	9.80 (2.80)	0.00	1.000	0.00
Standard MBI	20	9.30 (2.20)	9.55 (2.63)	−0.86	.398	0.19
Extended MBI	20	8.80 (2.67)	8.30 (2.83)	1.03	.315	−0.23
Total	60	9.30 (2.37)	9.22 (2.79)	0.34	.733	−0.04
NAB digits backward (raw score)
Brief MBI	20	6.85 (3.17)	6.55 (2.74)	0.66	.516	−0.15
Standard MBI	20	5.10 (2.10)	5.25 (2.53)	−0.45	.659	0.10
Extended MBI	20	5.45 (2.74)	5.65 (2.35)	−0.50	.624	0.11
Total	60	5.80 (2.77)	5.82 (2.56)	−0.07	.942	0.01
Phonemic fluency (total raw score)
Brief MBI	20	51.40 (14.30)	54.40 (16.27)	−1.49	.152	0.33
Standard MBI	20	42.45 (12.07)	46.00 (14.53)	−1.91	.071	0.43
Extended MBI	20	40.85 (10.54)	44.95 (12.98)	−2.06	.054	0.46
Total	60	44.90 (13.06)	48.45 (15.03)	−3.20	.002	0.41

^*Positive effect sizes indicate improvement, and negative effect sizes indicate worsening.

MBI, mindfulness-based intervention; NAB, neuropsychological assessment battery; RBANS, repeatable battery for the assessment of neuropsychological status.

Posttreatment was at 4 weeks for Brief MBI, 8 weeks for standard MBI, and 12 weeks for extended MBI.

Figure 3.

Within-group and total sample effect sizes for changes in neurocognitive outcomes from baseline to posttreatment. Brief = 4-week Mindfulness-based intervention (MBI). Standard = 8-week MBI. Extended = 12-week MBI. PROMIS Cog Fx, Patient-Reported Outcomes Measurement Information System Cognitive Function; Trail A, Trail Making A; Trail B, Trail Making B; RBANS Immed Mem, Repeatable Battery for the Assessment of Neuropsychological Status Immediate Memory Index Score; Vis Con, Visuospatial/Constructional Index Score; Lang, Language Index Score; Atten, Attention Index Score; Delay. Mem, Delayed Memory Index Score; Stroop Word, Stoop Word; Stroop Color, Stroop Color; Stroop C-W, Stroop Color-Word; NAB Digits Fwd, Neuropsychological Assessment Battery Digits Forward Raw Score; NAB Digits Back, NAB Digits Backward Raw Score; Phon Fluen, Phonemic Fluency (total score for three trials).

Discussion

PWN have poor HRQoL and current treatments do not adequately address this problem due to challenges with accessibility and treatment engagement stemming from narcolepsy symptoms. The present study provides preliminary evidence for the acceptability of MBI in PWN and the feasibility of using telehealth and remote data collection. Furthermore, there were indications that MBI is capable of improving several domains of HRQoL in PWN. These findings support the concept of using MBI as a complementary approach to standard medical treatment for narcolepsy in order to target psychosocial functioning. Together, this model could be used to address a major clinical care gap for narcolepsy.

The first aim was to evaluate the feasibility and acceptability of telehealth-delivered MBI for PWN. Adaptations to the MBI program and remote delivery and data collection strategies were implemented to improve the relevance, accessibility, and engagement for PWN with consideration of narcolepsy symptoms that could interfere with treatment. Overall, 71.7% met the benchmark of attending ≥80% of sessions (78.3% including those who later watched video recordings of missed sessions), with higher levels in the brief MBI (75%) and extended MBI (75%) groups relative to the standard MBI group (65%). After only one session, MBI was seen as logical with moderate expectations for success while at the end of the program, participants reported a high likelihood to refer MBI to other PWN. Qualitative data from exit interviews were generally consistent, with positive comments about the remote delivery and group format. Interestingly, most participants favored a longer program, and many who received the brief MBI were dissatisfied with the limited number of sessions. These findings show that the majority of PWN found the MBI program and telehealth format acceptable and accessible with a preference for more than four sessions. Practicing mindfulness meditation is the main behavioral component of MBI and 61.7% of participants met the benchmark of practicing ≥4 days per week, with the highest adherence in the brief MBI group (80%) and the lowest adherence in the standard MBI group (40%). Notably, participants reported an average of 178.06 minutes of meditation practice per week, which is slightly below the recommendation of 30 minutes of practice each day. However, PWN noted difficulty staying awake during the body scan meditation and many participants felt that the program content could be better connected to specific narcolepsy symptoms. These findings indicate that PWN are capable of engaging in meditation practice and accepting mindfulness principles, but additional tailoring could enhance participant engagement in MBI.

The feasibility of several study methods was also supported. The enrollment pace was ≥4 participants per month, supporting the feasibility of using these recruitment methods for randomization with group-based interventions. The remote data collection procedures were also generally supported, with only 5.83% of participants failing to provide complete data for baseline and posttreatment. A greater percentage of brief and extended MBI participants provided complete data relative to standard MBI. Out of all the baseline and posttreatment administrations of neurocognitive measures, only 10.83% of instances had missing neurocognitive data, supporting the use of synchronous videoconferencing and mail delivery of test forms. Finally, MBI teachers who are not sleep specialists were successfully trained to work with PWN and deliver the program using telehealth.

Given the position of this study as a feasibility trial, we reported on a wide range of clinical outcomes and used Cohen’s d ≥ 0.5 as the MCID for indications of clinical impact. Improvements in clinical measures should be interpreted with caution; however, given the lack of a control group. First, all versions of MBI met the MCID on mindfulness and self-compassion measures with moderate to large effect sizes. This important finding indicates that PWN are capable of acquiring mindfulness and self-compassion principles, the putative psychological mechanism of MBI, within a 4-to-12-week period. On PROMIS measures, all versions of MBI met the MCID threshold on self-efficacy for managing emotions, positive psychosocial impact, global mental health, and fatigue. This finding is generally consistent with previous research on the use of MBI in other chronic conditions [44–46], and also suggests that similar mechanisms could apply to narcolepsy. When examining the pattern for each MBI version, the extended MBI demonstrated the greatest clinical impact, meeting the MCID threshold on several HRQoL domains related to emotional, social, and cognitive functioning as well as self-efficacy and negative psychosocial impact. Interestingly, extended MBI also met the MCID threshold on the ESS, indicating that mindfulness could have an enhanced impact on reducing the core symptoms of excessive daytime sleepiness. Standard MBI also met the MCID threshold on several PROMIS domains but slightly fewer than extended MBI, while brief MBI met the MCID threshold on the fewest PROMIS domains. These patterns indicate that a more gradual, extended format of MBI appears to yield the greatest clinical impact across HRQoL domains in PWN. Notably, brief MBI met the MCID threshold on objective neurocognitive assessment of immediate memory and attention, while both brief and extended MBI met the MCID threshold on selective attention processing speed. These preliminary findings suggest that MBIs might be capable of improving cognitive functioning in areas that have relevance to narcolepsy symptoms and cultivation of mindfulness. Indeed, prior research has shown a relationship between greater mindfulness and greater attentional control, as well as greater attentional control amongst meditators than non-meditators [47].

Limitations

This feasibility study has several limitations. First, this study was not designed to evaluate efficacy, as there was no control condition and the sample size was not adequately powered for analyses comparing the MBI arms or comparing diagnostic groups. The lack of a control condition limits the extent to which any improvements observed can be attributed to the intervention itself. Furthermore, we presented data across several clinical domains with no formal hypothesis testing or adjustments for multiple comparisons. Although the suggested clinical impact of MBI is encouraging, the results should be interpreted with caution until further evidence of efficacy is established. Second, the sample was rather homogenous with regard to gender, race, and ethnicity. This indicates a need for more targeted efforts to include diverse samples and enhance generalizability of findings in future studies. Third, participants were not blinded to treatment conditions, which could have biased responses on self-reported measures.

Conclusions

Collectively, these findings support the need for testing to evaluate the efficacy of MBI for improving psychosocial functioning among PWN. Results suggest that an extended 12-week version of MBI may provide the most favorable clinical impact while maintaining high levels of session attendance and engagement in meditation practice. Enhancing the relevance of mindfulness concepts to specific narcolepsy symptoms could further tailor MBI for PWN. The findings also suggest that the remote delivery and data collection methods are feasible to employ in future clinical trials. Finally, there is a need to test the conceptual model that mindfulness and self-compassion acquired through mindfulness meditation are the underlying mechanisms that lead to changes in psychosocial functioning.

These findings dovetail with our previous work in developing a cognitive-behavior therapy for hypersomnia (CBT-H) [48]. One important difference between MBI and CBT-H is that CBT-H is intended to be delivered by a behavioral sleep medicine specialist, which requires specialty training, potentially limiting the scalability of this approach. In contrast, MBIs are intended to be delivered by non-specialists and we demonstrated the feasibility of training MBI teachers to work with PWN in a short time period. Collectively, the goal of these programs is to provide PWN with more evidence-based treatment options for addressing HRQoL.

Supplementary material

Supplementary material is available at SLEEP online.

Disclosure Statements

Financial disclosure: This publication was made possible by grant number R34AT009551 from the National Center for Complementary and Integrative Health (NCCIH). The contents of this publication are solely the responsibility of the authors and do not necessarily represent the official views of NCCIH. RSF was supported by grant number K08247973 from the National Cancer Institute (NCI) at the National Institutes of Health. This study was supported with resources from the Northwestern University Clinical and Translational Sciences Institute (NUCATS). NUCATS is funded in part by a Clinical and Translational Science Award grant from the National Institutes of Health (UL1TR001422). Nonfinancial disclosure: None.