Postpartum depression (PPD) is one of the most common complications of childbirth, affecting 1 in 5 mothers. Left untreated, it increases the risk of future depressive episodes and can have profound effects on offspring. A single case of PPD has been estimated to cost as much as $150,000 over the lifespan, or $3 billion for each annual cohort of Canadian births.~Current clinical practice guidelines (including those written by the NPA) recommend evidence-based psychotherapies (e.g., cognitive behavioural therapy (CBT)) as 1st-line treatments for the vast majority of mothers with PPD. The key role that psychotherapy plays in the treatment of PPD is further emphasized by the US Preventive Services Task Force which recommends universal PPD screening, but only when CBT or other evidence-based counseling is available.~While treating PPD can reduce its adverse effects, safe, timely, accessible interventions are essential to optimizing outcomes. However, only treatments that can be upscaled can have an impact on PPD at the population level.~The delivery of psychotherapy in large groups (up to 30 participants) is a relatively new phenomenon, but may be capable of addressing mothers' needs, as well as treating PPD on the scale required to address its prevalence. Brief (i.e., 1-Day) interventions contain the core content of more comprehensive, evidence-based interventions, but their brevity makes them easier to disseminate beyond traditional treatment settings (e.g., in public health). 1-Day CBT-Based Workshops have been delivered by trained mental health professionals (psychologists, psychiatrists) to treat generalized anxiety disorder and depression in general population samples, and postpartum depression.~The purpose of this pilot study is to determine the feasibility of our study procedures and estimate the treatment effect and variance of the primary outcome in preparation for a larger RCT to determine the effectiveness of a Public Health Nurse-Delivered 1-Day Cognitive Behavioural Therapy-Based Workshop for postpartum depression.~A parallel-group Ontario-wide RCT with experimental (workshop) and TAU (control) groups will address our objectives. Participants in both groups will complete all study questionnaires and be compared at baseline, and 3 and 6 months.~The experimental group will receive the Online 1-Day workshop (delivered by 2 PHNs) in addition to TAU, and the control group will receive TAU alone.~Participants will be mothers who have an infant under 12 months, who are 18 years or older, who are experiencing elevated symptoms of postpartum depression and who are free of current bipolar, psychotic and/or substance use disorders.
Public Health Nurses received training to deliver a day-long Cognitive Behavioural Therapy-based workshop for treating postpartum depression. Participants in the study are randomly assigned to the treatment group (1-day CBT workshop) or control group (usual postnatal care). Data will be collected from all participants at baseline, 3 and 6 months.~The study will aim to assess the feasibility of our methods and estimate the treatment effect of the primary outcome in preparation for a larger RCT. Objectives include:~Recruit and randomize 96 participants within 5 months~Questionnaire completion - 75% of participants complete all three questionnaires and structured interviews~Retention - 75% of participants remain in study until completion~75% of participants in treatment group complete the intervention~Estimate treatment effect and variance