0397 Efficacy of second-stage clinician-led CBTI in non-responders to digital CBTI: Is alleviation of cognitive arousal a mechanism?

Abstract

Abstract Introduction Cognitive-behavioral therapy for insomnia (CBTI) is first-line treatment for insomnia, but a provider shortage limits access. eHealth technology can increase access to behavioral interventions, and digital CBTI (fully automated programs) are effective. However, >50% of digital CBTI patients do not remit, and non-remission is linked to undertreated cognitive arousal, a central feature of insomnia. In a randomized controlled trial, we randomized digital CBTI non-remitters to second-stage clinician-led CBTI or control. We evaluated whether second-stage CBTI effectively reduced insomnia and depression, and tested whether reductions in cognitive arousal mediated these effects. Methods 207 patients whose insomnia did not remit with digital CBTI presented to second-stage therapy. Patients were randomized to clinician-led CBTI or sleep education control via telemedicine. Study outcomes included insomnia (insomnia severity index, ISI), depression (quick inventory of depressive symptomatology self-report 16-item survey, QIDS-SR16), and three indices of cognitive arousal (pre-sleep arousal scale’s cognitive factor [PSASC], perseverative thinking questionnaire [PTQ], and daytime insomnia symptoms response scale [DISRS]). Results Before second-stage therapy, all patients reported clinically significant insomnia (ISI≥10), 13.0% reported moderate depression, and 69.5% reported high cognitive arousal. Step 2 CBTI patients, relative to Controls, reported larger decreases in ISI (-6.43±4.31 vs -2.58±4.83, t=6.05, p<.001, Cohen’s d=.84). At posttreatment, 56.3% of Step 2 CBTI patients remitted (ISI≤7) relative to just 16.3% of Controls (Χ2=35.77, p<.001, RR=3.45). CBTI patients reported larger reductions in depression relative to control, which was a small-to-medium effect (-2.63±3.11 vs -1.11, t=3.15, p=.002, Cohen’s d=.44). Contrary to hypotheses, Step 2 CBTI did not reduce cognitive arousal relative to Control as measured by the PSASC (p=.195), PTQ (p=.840), and DISRS (p=.643). Conclusion Clinician-led CBTI is effective for alleviating symptoms of insomnia and comorbid depression in insomnia patients who do not initially remit with digital CBTI. Contrary to hypotheses, reducing cognitive arousal did not mediate treatment effects. As most insomnia non-remitters present to second-stage therapy with high cognitive arousal, alternative approaches that better target cognitive arousal symptoms may represent viable second-stage therapy options for insomnia. Support (if any) This RCT (NCT03322774) was supported by NIMH R01-MH122636.