Cognitive behavioral therapy (CBT) for insomnia has a noticeable impact on worry and a modest impact on rumination, according to a systematic review and meta-analysis. A study recently published in Sleep Medicine Reviews analyzed 7 databases to evaluate the effect of insomnia-targeted CBT on repetitive negative thinking (RNT). RNT is associated with sleep issues and exacerbates insomnia. Further, preliminary evidence shows that addressing RNT in insomnia treatment may improve depression and anxiety symptoms.
Researchers searched 7 databases from inception to October 2019: Pubmed, Medline, Scopus, PsycINFO, Psycarticles, Web of Science, and CINAHL. They assessed eligibility using the population-intervention-comparison-outcomes-study design (PICOS) approach. Grey literature was not included. They used the Cochrane tool to investigate bias risk. After applying inclusion and exclusion criteria, 15 studies made the cut.
CBT for insomnia’s effect on worry was “significant and moderate” [k = 6, g = -0.41, [95% CI = -0.75 to -0.07], P = .017]. Effect on sleep-related worry was “large and significant” [k = 7, g = -0.71, [95% CI = -0.92 to -.49], P < .0001]. Effect on rumination was “small and nonsignificant” [k = 3, g = -0.13, [95% CI = -1.10 to =0.83], P = .784]. The researchers did not find statistically significant association between post-treatment improvement in worry and depression.
Limitations of this study were the small number of available studies that fit the researchers’ criteria limited statistical power.
“Future, well-designed studies employing validated and reliable measures of RNT are utmost needed in order for future follow-up reviews to verify our preliminary findings,” the researchers concluded. “Furthermore, RCTs adopting measures of RNT and psychopathology are needed to advance the knowledge on the effects of CBT-I on mental health.”
Ballesio A, Bacaro V, Vacca M, et al. Does cognitive behaviour therapy for insomnia reduce repetitive negative thinking and sleep-related worry beliefs? A systematic review and meta-analysis (published online September 11, 2020). Sleep Med Rev. doi: 10.1016/j.smrv.2020.101378