Effects of a guided digital intervention on sleep and mental health outcomes in university students: a randomized controlled trial
Abstract
Study Objectives To evaluate the effectiveness of a guided digital intervention targeting sleep and circadian rhythms in university students.Methods We randomized 195 university students with self-reported insomnia (Insomnia Severity Index >= 10) from nine Dutch Universities to receive either the 5-week guided digital cognitive-behavioral therapy for insomnia "i-Sleep & BioClock", or digital sleep psychoeducation and sleep monitoring. Online assessments were at baseline, 3 (mid-treatment), 6 (post-treatment), and 18 (follow-up) weeks. The primary outcome was insomnia severity at 6 weeks. Secondary outcomes were symptoms of depression and anxiety; functioning; quality of life (QoL); academic performance; and sleep and light exposure diary outcomes.Results From Nov 1st 2023 until Sept 5th 2024, we randomly assigned 96 students (age 23.8 +/- 3.8, 75.4% female) to the intervention and 99 to the control condition, stratified by university and gender. Fifty-one percent completed the post-treatment assessment, and 30% the follow-up. 31% were intervention completers. Linear mixed models showed no significant time x treatment interaction for insomnia severity ("i-Sleep & BioClock": baseline ISI M = 16.8, SD = 4.0; post-treatment ISI M = 10.2, SD = 3.9; Digital psychoeducation: baseline ISI M = 16.5, SD = 3.6; post-treatment ISI M = 11.1, SD = 4.2). The difference in change between groups was -1.17 points (95% CI -2.72 to 0.38), p=.14, Cohen's d = -0.31. Most secondary outcomes showed no significant time x treatment effects.Conclusions "i-Sleep & BioClock" was not more effective than online psychoeducation on most outcomes, possibly due to active elements present in both conditions or low adherence. Future research should identify factors for early disengagement and investigate which intervention components drive improvements in sleep.Clinical Trial Effectiveness of a Guided Self-help Intervention for Improving Sleep in University Students, https://clinicaltrials.gov/study/NCT06023693, prospectively registered at ClinicalTrials.gov on August 3rd, 2023.Statement of Significance Sleep problems are highly prevalent among university students and are associated with poor mental health, functioning, and academic outcomes. Students struggle to maintain a 24-hour rhythm which is why we enhanced a digital CBT-I intervention with elements targeting the circadian rhythm. Although there is considerable evidence to support the effectiveness of CBT-I in various populations, this study shows that digital CBT-I is not superior to digital psychoeducation and sleep monitoring in students. Both groups showed notable improvements, likely reflecting active elements in both conditions. Low adherence may also have diminished the between-group effects. Future research should explore the potential of brief digital sleep interventions, barriers to adherence, and investigate which intervention components drive improvements in sleep.

