 This project will assess the effectiveness of a stepped-care model i.e. digital Cognitive Behavioral Therapy for Insomnia dCBT-I followed by face-to-face CBT-I in improving severity of insomnia and sleep outcomes in an insomnia cohort, including those at higher risk of depression. This project will also investigate the effectiveness of this stepped-care model in prevention of depression and any potential mediation by rumination as a modifiable behavior. 