Efficacy of Email-delivered Versus Face-to-face Group Cognitive Behavioral Therapy for Insomnia in Youths: A Randomized Controlled Trial

The purpose of the study was to compare the efficacy of group-based therapy (GT) and email-delivered self-help (ESH) cognitive behavioral therapy for insomnia (CBT-I) with the wait-list (WL) control group in youths.The study involved an assessor-blind, parallel group randomized controlled trial in youths meeting the diagnostic criteria for insomnia disorder. Participants were randomized to one of the three groups (8-week GT, 8-week ESH, or WL). Participants in all three groups were assessed at baseline and after treatment (week 9 for the WL group). The two treatment groups were additionally assessed at one month and six months after the intervention. Treatment effects were examined using linear mixed models.A total of 135 youths (mean age: 20.0 ± 2.5 years, female: 67.4%) were recruited. After treatment, both active treatment groups showed significant improvements in insomnia symptoms (GT vs. WL: Cohen's d = -1.03, ESH vs. WL: d = -.63), less presleep arousal (d = -.52 to -1.47), less sleep-related dysfunctional belief (d = -.88 to -1.78), better sleep hygiene practice (d = -.79 to -.84), and improved daytime functioning (d = -.56 to -.96) compared with the WL group. In addition, GT outperformed ESH in improving maladaptive sleep-related beliefs and mood symptoms at post-treatment and 6-month follow-up. A reduction of suicidality with moderate effect size favoring GT emerged at 6-month follow-up.Our findings suggested that both group-based and email-delivered CBT-I were effective in treating youth insomnia, but group-based CBT-I showed superior effects on reducing maladaptive beliefs and mood symptoms.