Sleep restriction therapy for insomnia is associated with reduced objective total sleep time, increased daytime somnolence, and objectively impaired vigilance: implications for the clinical management of insomnia disorder

Kyle, S. D., Miller, C. B., Rogers, Z., Siriwardena, A. N., Macmahon, K. M. and Espie, C. A. (2014) Sleep restriction therapy for insomnia is associated with reduced objective total sleep time, increased daytime somnolence, and objectively impaired vigilance: implications for the clinical management of insomnia disorder. Sleep, 37(2), pp. 229-237. (doi: 10.5665/sleep.3386)

Abstract

Study Objectives: To investigate whether sleep restriction therapy (SRT) is associated with reduced objective total sleep time (TST), increased daytime somnolence, and impaired vigilance.<p></p> Design: Within-subject, noncontrolled treatment investigation.<p></p> Setting: Sleep research laboratory.<p></p> Participants: Sixteen patients [10 female, mean age = 47.1 (10.8) y] with well-defined psychophysiological insomnia (PI), reporting TST ≤ 6 h.<p></p> Interventions: Patients were treated with single-component SRT over a 4-w protocol, sleeping in the laboratory for 2 nights prior to treatment initiation and for 3 nights (SRT night 1, 8, 22) during the acute interventional phase. The psychomotor vigilance task (PVT) was completed at seven defined time points [day 0 (baseline), day 1,7,8,21,22 (acute treatment) and day 84 (3 mo)]. The Epworth Sleepiness Scale (ESS) was completed at baseline, w 1-4, and 3 mo.<p></p> Measurement and results: Subjective sleep outcomes and global insomnia severity significantly improved before and after SRT. There was, however, a robust decrease in PSG-defined TST during acute implementation of SRT, by an average of 91 min on night 1, 78 min on night 8, and 69 min on night 22, relative to baseline (P < 0.001; effect size range = 1.60-1.80). During SRT, PVT lapses were significantly increased from baseline (at three of five assessment points, all P < 0.05; effect size range = 0.69-0.78), returning to baseline levels by 3 mo (P = 0.43). A similar pattern was observed for RT, with RTs slowing during acute treatment (at four of five assessment points, all P < 0.05; effect size range = 0.57-0.89) and returning to pretreatment levels at 3 mo (P = 0.78). ESS scores were increased at w 1, 2, and 3 (relative to baseline; all P < 0.05); by 3 mo, sleepiness had returned to baseline (normative) levels (P = 0.65).<p></p> Conclusion: For the first time we show that acute sleep restriction therapy is associated with reduced objective total sleep time, increased daytime sleepiness, and objective performance impairment. Our data have important implications for implementation guidelines around the safe and effective delivery of cognitive behavioral therapy for insomnia.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Espie, Professor Colin and Rogers, Ms Zoe and Macmahon, Dr Kenneth and Kyle, Dr Simon
• Authors: Kyle, S. D., Miller, C. B., Rogers, Z., Siriwardena, A. N., Macmahon, K. M., and Espie, C. A.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Sleep
• Publisher: Associated Professional Sleep Societies, LLC
• ISSN: 0161-8105
• ISSN (Online): 1550-9109

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
54046	1	Objective impact on sleep and daytime functioning of sleep restriction therapy: a brief behvioural intervention for persistent insomnia	Colin Espie	Scottish Executive Health Department (SEHHD-CSO)	CZG/2/503	RI NEUROSCIENCE & PSYCHOLOGY
42151	4	Attention bias as an etiologic factor in primary and secondary insomnia	Colin Espie	National Institute of Health (USA) (NIH(US))	5R01MH077901-04	RI NEUROSCIENCE & PSYCHOLOGY