Insomnia Nervous System Diseases
Conditions
Interventions
Sleep restriction therapy (SRT) involves prescribing a restricted time in bed (TIB, ‘sleep window’) based on an individual’s reported duration and pattern of sleep. The estimated total sleep time (TST
Sponsors
University of Oxford
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: 1. Participant is willing and able to give informed consent for participation in the study. 2. Male or Female, aged 25-55 years 3. Screen positive for persistent insomnia (chronicity >3 months) as indicated on the Sleep Condition Indicator and meet DSM-5 criteria for insomnia disorder 4. Sleep efficiency < 85% 5. Intermediate chronotype as indicated by the Morningness-Eveningness questionnaire (score between 31 and 69) 6. Participant is able to comply with study procedures 7. Body mass index between 18 and 30 kg/m2
Exclusion criteria
Exclusion criteria: 1. Clinically significant anxiety or depressive symptoms (Anxiety (HADS) > 10) 2. Psychiatric diagnoses other than insomnia 3. Previous or current engagement with psychological treatment for insomnia (by healthcare professional or online) 4. Additional sleep disorder diagnosis or positive screen (e.g. Narcolepsy, circadian rhythm disorder) 5. Sleep-disruptive medical comorbidity or conditions contraindicated for SRT (e.g. epilepsy) 6. Current prescription of CNS or hormonal medication 7. Overnight, early morning, evening, or rotating shift work in the last 3 months 8. Pregnancy, lactation, perimenopausal or menopausal 9. Travelled across more than 2 time zones in the prior 3 months 10. Smoked more than 5 cigarettes/week in the previous 3 months 11. Consumed more than 300mg of caffeine per day on average 12. Extreme alcohol consumption (score >10 on the alcohol use disorders identification test = AUDIT) 13. Any comorbidities that are causing the sleep problems 14. History of drug abuse in the past 12 months
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The Phase angle (in minutes) between dim light melatonin onset (DLMO) and average attempted sleep over the past 7 days, measured by sleep diary (Phase angle = attempted sleep time – clock time of the DLMO) at baseline and post-treatment. DLMO will be measured by hourly collected saliva samples under standardised, dim light conditions at the sleep laboratory over an 8-9 hour period. | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. DLMO at baseline and post-treatment 2. Subjective and objective sleep consolidation at baseline and post-treatment indexed via the following sleep parameters: SE, SOL, and WASO 3. Repeated hourly assessment of subjective alertness (sleepiness question) and objectively-measured sustained attention (PVT) obtained at the laboratory sessions at baseline and post-treatment 4. Insomnia severity assessed by the ISI at baseline and post-treatment 5. Daytime impairments assessed by the ESS and the BC-CCI at baseline, after the first week of treatment and after the second week of treatment (post-treatment) 6. Daily changes in mood assessed by 6 mood items (3 negative, 3 positive) included in the evening part of the sleep diary and measured continuously over the whole study period (1 week baseline, 2 weeks treatment) 7. Daily changes in pre-sleep arousal (5 items of the pre-sleep arousal scale) and sleep effort as assessed by the morning part of the sleep diary and measured continuously over the whole study period (1 week baseline, 2 weeks treatment) | — |
Countries
United Kingdom
Outcome results
None listed