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Is digital cognitive behavioural therapy for insomnia effective in treating sub-threshold insomnia: a pilot RCT

Research output: Contribution to journalArticle

Dan Denis, Thalia C. Eley, Fruhling Rijsdijk, Helena M.S. Zavos, Robert Keers, Colin A. Espie, Annemarie I. Luik, Isabella Badini, Sarah Derveeuw, John Hodsoll, Alice M. Gregory

Original languageEnglish
Pages (from-to)174-183
Number of pages10
JournalSleep Medicine
Publication statusPublished - 1 Feb 2020

King's Authors


Objective/Background: Many patients find cognitive behavioral therapy for insomnia (CBT-I) useful. However, it is currently unknown if those with sub-threshold insomnia also benefit. Here we assessed whether CBT-I is both feasible and acceptable in participants with sub-threshold insomnia. The primary aims were to evaluate participation rates and treatment acceptability, and to establish an effect size for symptom improvement. Patients/Methods: A total of 199 female participants (Mage 20 ± 5 years) took part. Following baseline assessments, participants were randomly allocated to either a six-week digital CBT-I intervention or a six-week control group receiving puzzles. Additional assessments were performed three-weeks, six-weeks, and six-months later. Results: Participation rates at each survey assessment wave did not differ between the groups (ps > 0.140), though adherence to completing each weekly task was lower in the CBT-I group, p = 0.02. Treatment acceptability was high (M (SD) = 33.61 (4.82), theoretical range 6–42). The CBT-I group showed greater improvement in insomnia symptoms at the end of the intervention compared to the control group (p = 0.013, d = 0.42), with significant variation in outcome (M = 4.69, SD = 5.41). Sub-threshold participants showed a similar pattern of results, whilst those meeting insomnia criteria showed a smaller between-group difference. CBT-I led to improvements in anxiety, paranoia and perceived stress between baseline and end of intervention. Changes in insomnia symptoms were mediated by cognitions about sleep and somatic pre-sleep arousal. Conclusions: CBT-I provides a benefit even in sub-threshold insomnia. CBT-I may be useful to tackle insomnia symptoms even when they are sub-threshold.

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