This study aims to test the efficacy of group-based cognitive behavioural therapy for insomnia (CBT-I) and app-based CBT-I (developed by a group of psychiatrists and clinical psychologists) in combination with usual care (UC) in reducing the severity of insomnia and depression in pregnant women with comorbid insomnia and depression, when compared with UC plus group-based health-related psychoeducation control. This study also examines the effects of group-based CBT-I and app-based CBT-I on subjective and objective sleep and mood measures, quality of life measures as well as mother-infant-relationship.