JADXXX10.1177/1087054714529456Journal of Attention DisordersSobanski et al.
Daytime Sleepiness in Adults With ADHD: A Pilot Trial With a Multiple Sleep Latency Test
Journal of Attention Disorders 1–7 © 2014 SAGE Publications Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1087054714529456 jad.sagepub.com
Esther Sobanski1, Barbara Alm1, Oliver Hennig1, Dieter Riemann2, Bernd Feige2, and Michael Schredl1
Abstract Objective: To evaluate sleep latency (SL) during the multiple sleep latency test (MSLT) and subjective daytime sleepiness in adult ADHD and controls. Method: Subjective daytime sleepiness was assessed by Epworth Sleepiness Scale (ESS) in 27 unmedicated adults with ADHD and in 182 controls. Thirteen ADHD patients and 26 controls underwent MSLT after one night of polysomnography (PSG). Results: Mean MSLT-SL was 10.6 ± 4.8 min in ADHD and 12.2 ± 4.2 min in controls (n.s.). Mean ESS score was 9.3 ± 4.9 points in ADHD and 6.9 ± 3.4 points in controls (p < .005). MSLT-SL and ESS scores correlated inversely by trend (r = −.45, p < .1) but not with ADHD symptoms or ADHD subtype. Conclusion: Adults with ADHD do not differ from controls in mean MSLT-SL but experience increased subjective daytime sleepiness. Patients with subjective higher daytime tiredness fell asleep faster during MSLT. ( J. of Att. Dis. XXXX; XX(X) XX-XX) Keywords ADHD, adults, multiple sleep latency onset test, daytime sleepiness, arousal
Introduction Sleep difficulties in childhood ADHD have been documented by numerous studies and meta-analyses (Corkum, Tannock, & Moldofsky, 1998; Cortese, Farone, Konofal, & Lecendreux, 2009). Studies examining sleep in adult ADHD are less numerous than in childhood ADHD but document similar pattern and prevalence of sleep problems as in children. Questionnaire studies examining subjective sleep measures consistently report sleep onset problems, restless and nonrestorative sleep, and increased daytime sleepiness in up to 80% of adult ADHD patients (Schredl, Alm, & Sobanski, 2007; Surman et al., 2009; Yoon, Jain, & Shapiro, 2013), and recent studies report a circadian preference toward eveningness (Baird, Coogan, Siddiqui, Donev, & Thome, 2012; Rybak, McNeely, Mackenzie, Jain, & Levitan, 2007). Studies assessing objective sleep parameters by polysomnography (PSG) or actigraphy report reduced sleep efficiency, longer sleep onset latencies, more nocturnal awakenings, and increased nocturnal activity in adult ADHD compared with healthy controls (Kooij, Middelkoop, van Gils, & Buitelaar, 2001; Philipsen et al., 2005; Sobanski, Schredl, Kettler, & Alm, 2008). Studies assessing objective daytime sleepiness in ADHD are still relatively sparse. To date, there are three studies that used the multiple sleep latency test (MSLT) in school-aged children with ADHD, which have yielded mixed results. Two studies report decreased sleep latency (SL) in ADHD
compared with controls (Golan, Shahar, Ravid, & Pillar, 2004; Lecendreux, Konofal, Bouvard, Falissard, & MourenSimeoni, 2000), while a recent study failed to find any difference in mean MSLT-SL in ADHD compared with controls (Prihodova et al., 2010). To the best of our knowledge, MSLT studies in adults with ADHD are still lacking. This is a crucial evidence gap, as results from MSLT studies in children cannot be transferred directly to adult ADHD, because sleep characteristics including duration of sustained wakefulness during the day and the need of daytime naps are related to developmental level and age. For scientific reasons, it is useful to extend the still inconsistent data on daytime sleepiness in ADHD as there is some evidence that pathophysiologic mechanisms underlying attention deficits in ADHD involve dysregulation of arousal (Benikos & Johnstone, 2009). A Consensus Working Group on ADHD and sleep recently identified hypoarousal and daytime sleepiness in ADHD as one of six future major key research areas (Owens et al., 2013). 1
Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany 2 University Medical Center Freiburg, Germany Corresponding Author: Esther Sobanski, Medical Faculty Mannheim, Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, J 5, 68159 Mannheim, Germany. Email: [email protected]
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Journal of Attention Disorders
The primary aim of the present study is to assess objective and subjective daytime sleepiness by MSLT-SL and by the self-rated questionnaire Epworth Sleepiness Scale (ESS) in adult patients with ADHD compared with healthy controls. Secondary aims of the study are to analyze the interplay of MSLT-SL and ESS scores, and the association of both sleep measures with current and childhood ADHD symptom severity and ADHD subtype according to Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association [APA], 1994) criteria.
have an IQ > 85 to exclude psychosocial impairment due to reduced intelligence level. Exclusion criteria for all participants were an apnea index > 5 during polysomnographic recording, obstructive snoring or working night shift, intake of any medication within 4 weeks including methylphenidate before the start of the study, any unstable psychiatric and medical condition, current substance abuse, more than 10 points in the Beck Depression Scale and/or clinically significant abnormal laboratory values, or a positive urinary drug screen.
Participants The study was approved by the local ethics committees. All participants gave written informed consent before participating in the study. Patients with ADHD were recruited from consecutive referrals at the Adult ADHD Outpatient Clinic at the Central Institute of Mental Health (CIMH), Mannheim, Germany. MSLT and other sleep parameters were assessed within a polysomnographic study evaluating the influence of methylphenidate treatment on sleep in adult patients with ADHD (Sobanski et al., 2008). Healthy controls were recruited by personal contact at the Departments for Sleep Medicine at the CIMH and at the Psychiatric University Hospital in Freiburg, Germany. MSLT in healthy controls was carried out at the Department for Sleep Medicine at the University of Freiburg within studies assessing the impact of psychopharmacological treatment on nocturnal sleep and daytime sleepiness (Doerr et al., 2010; Möller & Riemann, 2002). Patients and controls underwent a comprehensive semistructured clinical interview in which information about current psychiatric status and symptoms, sleep disturbances and disorders, medical status, and psychiatric and medical history was assessed. All interviews were performed by experienced clinicians. In addition, we performed a physical examination along with an evaluation of laboratory parameters for hematology, biochemistry, and thyroid parameters, as well as a urine drug test. For inclusion, all participants had to be 18 to 55 years old. Patients had to be diagnosed with ADHD according to DSM-IV criteria (APA, 1994) and according to expert consensus (E.S., B.A.). Childhood ADHD and chronic course of ADHD symptoms from childhood to adulthood were confirmed by collateral information (e.g., interviewing the patients’ parents, school reports) whenever possible. Clinical diagnosis of ADHD in patients was validated by standardized instruments. To be included, patients had to be rated with ≥15 points in the ADHD–Diagnostic Checklist (ADHD-DC; Rösler et al., 2004) and ≥30 points in the validated German Wender– Utah Rating Scale, Short Version (WURS-k; RetzJunginger et al., 2003). Patients were further required to
ESS. The ESS is a self-rated questionnaire used to determine the level of daytime sleepiness (Johns, 1991, 2000). It is widely used for clinical and research purpose (Geisler et al., 2006; Neu et al., 2008; Yoon et al., 2013) due to its ability to measure sleep propensity in different situations of daily living and to provide a reflection of general characteristic of sleepiness in daily life. Participants are asked to rate their propensity to doze off or fall asleep for eight different situations of daily living on a scale of increasing probability with a range from 0 to 3. Scores higher than 10 are indicative of clinically relevant daytime sleepiness. MSLT. Before MSLT, patients and controls spent a night in sleep laboratory for polysomnography (PSG). PSG encompassed electroencephalogram (EEG) (C3-A2, C4-A1), assessment of horizontal and vertical eye movements, submental and leg electromyogram, electrocardiogram, and assessment of respiration (oral and nasal air flow, thoracoabdominal respiratory movements, and oxygen saturation). All recordings were carried out from 11:00 p.m. (lights out) to 7:00 a.m. (lights on) and scored in 30-s epochs, according to Rechtschaffen and Kales’s (1968) criteria. MSLT was performed the day following PSG in 13 patients with ADHD and in 26 healthy controls. The same MSLT-protocol was used for ADHD and control participants. Most participants were given five opportunities to fall asleep every 2 hr. In 18 participants, MSLT recording comprised four assessments. MSLT recording times were 9:00 a.m., 11:00 a.m., 1:00 p.m., and 3:00 p.m., and for those with five recordings, 5:00 p.m., with every nap opportunity lasting 20 min. For each nap, participants were requested to lie in bed in a dark, quiet, and comfortable room, with no external stimulation and were asked to fall asleep. SL for each trial was measured from the time of lights out to the first epoch of sleep. The time taken to fall asleep (SL) and sleep stages attained are recorded by PSG. Standard methods were used for MLST evaluation where the occurrence of one epoch of sleep of any stage was rated as sleep onset. If participants did not fall asleep
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Sobanski et al. Table 1. Personal and Clinical Characteristics of ADHD Patients (n = 13) and Healthy Controls (n = 27) Participating in MSLT.
Age (years) Gender (n, % males) IQ WURS-k ADHD-DC Beck Depression Inventory Current psychiatric disorders Current medical disorders Urinary drug screen
ADHD (n = 13)
Controls (n = 27)
33.5 ± 9.4 10 (76.9) 115.8 ± 14.1 42.4. ± 12.2 28.9 ± 7.2 9.2 ± 3.8 Social phobia (n = 1) Mild motoric tics (n = 1) None Negative
26.7 ± 4.1 27 (100) — — — 1.9 ± 1.6 (n = 14) None