Efficacy of transdiagnostic cognitive-behavioral treatment for anxiety disorders on insomnia.

INTRODUCTION

The efficacy of transdiagnostic cognitive-behavioral therapy (tCBT) for anxiety disorders (AD) is well established. Few studies have investigated the role of insomnia in the context of tCBT for AD. Considering the high prevalence of insomnia symptoms in individuals with AD, this study aims to explore the effects of tCBT on insomnia, as well as to examine the predictive or moderating role of insomnia on the efficacy of tCBT for AD.

METHOD: The present study consists of a secondary analysis of data from a randomized clinical trial of tCBT for AD (Roberge et al., 2022). The 231 participants with panic disorder, agoraphobia, generalized anxiety disorder and/or social anxiety disorder were randomized to an experimental group tCBT condition (Norton, 2012) combined with usual care (TAU) compared with a TAU-only control condition.

RESULTS

The efficacy of tCBT for insomnia symptoms is supported by linear mixed regression analysis, where participants receiving tCBT achieved significantly lower insomnia symptoms at post-treatment than TAU-only participants (unadjusted mean at post-treatment, 9.98 ± 6.72 vs. 13.13 ± 6.41, p < .001, Cohen's d = 0.48), with progress maintained through 12-month follow-up. Results showed a moderator role of ISI where participants with high insomnia symptoms at pre-treatment had higher anxiety symptoms at post-treatment in all conditions, with stronger improvement over time in the tCBT condition.

CONCLUSION

The study highlights the importance of considering insomnia symptoms in the clinical context of tCBT for AD and of developing and evaluating intervention modalities that would optimally address this frequent comorbidity.