Daytime sleepiness, driving performance, reaction time and inhibitory control during sleep restriction therapy for Chronic Insomnia Disorder.

BACKGROUND: Sleep restriction therapy (SRT) is a largely untested single treatment component of cognitive-behaviour therapy for insomnia. To date, the evidence for contraindications for SRT is limited to very few studies. The present study investigated the objective and subjective daytime consequences during the acute phase of SRT for adults diagnosed with Chronic Insomnia Disorder.

METHODS: Sixteen adults (age = 36.3 ± 13.4 yrs, 12 females, 4 males) underwent SRT for their insomnia over a two week period based on recommendations by Miller and colleagues (2014) [6]. Participants completed sleep diaries, self-reported daytime sleepiness (Epworth Sleepiness Scale [ESS]), as well as objective measures of reaction time/inhibition (Go/NoGo task) and driving performance (AusEd driving simulator) at pre-, mid- (ie, after one week of SRT) and post-SRT (after two weeks of SRT).

RESULTS: Sleep diary outcomes indicated participants complied with the restriction of time in bed, and that a similar amount of total sleep time (TST) was maintained from pre-to-post-treatment. There was no significant change in daytime sleepiness, and similarly no significant changes observed in objective performance on the Go/NoGo task and AusEd driving simulator.

CONCLUSIONS: These preliminary results suggest SRT during the acute phase does not appear to place insomnia patients at risk of significant impairments in sleepiness and reaction times. We note these findings can only be translated into clinical practice when sleep duration remains relatively unchanged. Future studies using objective measures of sleep and a control group are recommended.