BACKGROUND: Cognitive behavioural therapy for insomnia (CBT-I) is the recommended first-line treatment for insomnia. However, scaling this proven effective intervention to areas of high need remains a challenge, necessitating sensitive adaptation and evaluation. METHODS: A randomised waitlist-controlled trial evaluated the efficacy of a hybrid digital CBT-I and emotion regulation (dCBT-I + ER) intervention delivered through workplaces. Participants with at least mild insomnia and depression or anxiety symptoms were randomised to the intervention or waitlist control groups. The intervention was delivered via a web-based platform and four video-conferencing therapy sessions. Participants tracked their sleep using actigraphy and a sleep diary that was used to pace the intervention delivered. Assessments occurred at baseline and 8 weeks post-randomisation, measuring insomnia, depression, anxiety, psychological well-being, quality of life, and work productivity. RESULTS: Of the 159 participants (mean age 43.6 ± 9.4 years, 76.7% female, 80.5% white), 80 received the intervention and 79 were in the control group. The intervention group showed significant improvements in insomnia (F1, 134 = 71.46, p <
.0001)
depression (F1, 134 = 35.67, p <
.0001)
and anxiety (F1, 134 = 17.63, p <
.0001), with large effect sizes (d = 0.7-1.5). Sleep diary data supported these findings, whereas actigraphy data did not. Improvements in psychological well-being were significant (F1, 132.13 = 10.64, p <
0.001), whereas quality of life, work productivity, and satisfaction outcomes were not. CONCLUSIONS: This study suggests that a hybrid dCBT-I + ER intervention, delivered via workplaces, effectively improves insomnia, depression, and anxiety. It holds promise as a scalable solution, warranting further investigation into its long-term efficacy and economic impact.