Does cognitive behaviour therapy for insomnia reduce repetitive negative thinking and sleep-related worry beliefs? A systematic review and meta-analysis
Repetitive negative thinking (RNT), i.e., worry, rumination, and transdiagnostic repetitive thinking, is thought to exacerbate and perpetuate insomnia in cognitive models. Moreover, RNT is a longitudinal precursor of depression and anxiety, which are often co-present alongside insomnia. Whilst accumu- lating evidence supports the efficacy of cognitive behavioural therapy for insomnia (CBT-I) in reducing depression and anxiety symptoms, the literature on the effects of CBT-I on RNT has never been sys- tematically appraised.