Sleep–wake state discrepancy does not impair the efficacy of cognitive behavioural therapy for insomnia: Findings from a large clinic sample

Abstract

SummaryThe current study determined the extent to which sleep–wake state discrepancy impairs the efficacy of cognitive behavioural therapy for insomnia in a real‐world clinical sample. Sleep–wake state discrepancy occurs when there is an inconsistency between a person's subjective and objective sleep, and is a common phenomenon amongst patients with insomnia. Limited information is available on the effectiveness of cognitive behavioural therapy for insomnia in treating patients who experience significant sleep–wake state discrepancy in “real‐world” samples. In the present study, all patients with insomnia received cognitive behavioural therapy for insomnia through an outpatient insomnia program (N = 386; mean age = 51.96 years, SD = 15.62; 65.97% [N = 254] female). Prior to treatment, participants completed a polysomnography sleep study and sleep diary, which was used to calculate sleep–wake state discrepancy. At pre‐treatment, post‐treatment and 3‐month follow‐up, participants completed the Insomnia Severity Index and other questionnaires, and 1 week of sleep diaries from which sleep‐onset latency, wake after sleep onset and other sleep variables were calculated. There were no differences in self‐reported sleep‐onset latency, wake after sleep onset or Insomnia Severity Index scores at post‐treatment or 3‐month follow‐up between quintiles of sleep–wake state discrepancy. These results indicate that sleep–wake state discrepancy at pre‐treatment does not predict treatment response to cognitive behavioural therapy for insomnia. Future research could examine multi‐night assessments of sleep–wake state discrepancy to determine whether variations in discrepancy may relate to pre‐treatment insomnia severity and cognitive behavioural therapy for insomnia outcomes.