de Bruin EJ, et al. - The authors performed this study to examine whether cognitive behavioural therapy for insomnia (CBTI) improved psychopathology in Internet- (IT) and face-to-face group treatment (GT) compared to waitlist (WL). In addition, they investigated if improvement in psychopathology could be attributed to reduced insomnia, and improvement in psychopathology remained stable for up to 1 year. This study was the first to reveal that Internet and face-to-face CBT for insomnia achieved a long-term reduction in adolescent psychopathology, by improving insomnia. For youth mental health care, this finding could have profound implications.