Examining the Effectiveness of Transdiagnostic, Internet-Delivered Cognitive Behaviour Therapy in New Mothers Experiencing Anxiety and Depression

In the proposed study, the investigators will examine the efficacy of transdiagnostic, Internet-delivered cognitive behaviour therapy (ICBT) in the treatment of postpartum anxiety and depression. Half of participants will receive the treatment immediately, and half of the participants will be assigned to a treatment-as-usual control condition. Participants assigned to the control condition will be offered the treatment after a 12-week waiting period, although data from this portion will not be included in the current study. All participants will complete questionnaires prior to the start of the treatment, following treatment (or corresponding 8-week waiting period), at 1-months follow-up (or corresponding 12-week waiting period), and at 6-months follow-up (in those assigned to the treatment condition). Further, those who receive the treatment will complete questionnaires on a weekly basis. The primary outcome measures include anxiety and depression. As part of the battery of questionnaires administered after the completion of the program, participants will be asked to rate the program content, the overall service, and their satisfaction with the program.