ABSTRACT
PURPOSE: 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. METHODS: 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. RESULTS: 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. DISCUSSION: 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.
