Efficacy of repeated self-guided digital cognitive behavioral therapy for chronic insomnia: A pilot open-label study following a previous RCT

Objective: This study aimed to assess whether a second course of digital cognitive behavioral therapy for insomnia (dCBT-I) could benefit patients with chronic insomnia who had suboptimal responses to the initial fully self-guided dCBT-I. Methods: Building on a previous randomized controlled trial (RCT), participants with an Insomnia Severity Index (ISI) score ≥8 at 6 months after completing the initial digital CBT-I therapy were invited to enroll in the second phase of the study. Among the 20 eligible participants, 9 received a second round of digital dCBT-I therapy, 6 participated in follow-up only. Primary outcomes included changes in ISI scores and ISI remission rates (defined as ISI