The overarching aim of this project is to develop and pilot an innovative online intervention (Share) that integrates an Individual Internet Intervention (III) and an Internet Support Group (ISG) in preventing Postpartum Major Depression (PPMD). To establish that supportive accountability is a critical component of the intervention, Share will be compared to an III alone, and an ISG without the III components.

Postpartum major depression (PPMD) occurs in approximately 7% of women in the first three months after childbirth and up to 22% of women over the first year postpartum. The impact of PPMD can be profound, including emotional distress, impairment in daily functioning and especially in caring for an infant for women as well as disturbances in infant development. The need for preventive interventions that are effective and widely accessible is clear and widely recognized.

While several psychological interventions to prevent PPMD have demonstrated efficacy, all of these interventions require women to be physically present at a treatment site at a particular time and day. There are numerous well established access barriers to traditional face-to-face psychological interventions, particularly for postpartum women facing the demands of childcare, including cost, transportation barriers, and time constraints, all of which make it impossible for the vast majority of women to participate in preventive care. The Internet offers great potential in extending mental health services to perinatal women because it directly circumvents these barriers.

Two broad classes of internet interventions have been evaluated within medicine generally, although to date there are no published evaluations of such interventions among perinatal women: Individual Internet Interventions (IIIs), which provide patients with access to web-based self-management programs, and Internet Support Groups (ISGs), which are usually centered around a discussion board or chat room. Meta-analyses suggest that IIIs are effective with acutely depressed patients when they include regular support by live coach (d=.61), but are much less effective when they are provided as a stand-alone treatment (d=.25). The enhanced efficacy of coach-supported IIIs appears to be due to the greater adherence to the intervention (e.g. more frequent usage) resulting from personal coach contact. The obvious drawbacks are cost and scalability: infrastructures for the training, oversight and payment of coaches must be implemented.

In contrast, ISGs provide a vehicle for peer support, and are very highly valued and commonly used by perinatal women. However, while adherence may be good, trials have found unmoderated ISGs to be ineffective at reducing distress and depression, Taken together, the efficacy of the IIIs and the adherence, flexibility, and potential for peer support in an ISG suggest that peers in a well-constructed ISG that encourages support and collaborative learning, could enhance adherence and outcomes of online self-management training programs. Learning these self-management skills have proven effective in face-to-face interventions to prevent depression among perinatal women.

This intervention, which we call "Share", is based upon a unique combination of two critical concepts:

1. the capacity of IIIs to teach self-management skills; and
2. the potential for ISGs to enhance adherence and contribute to effective learning.

Inclusion Criteria:

Women who are:

1. 18 years and older
2. Pregnant and between 20 and 28 weeks gestation and for whom there is an expectation of a full 40 week gestation at the birth of their child
3. Have a Patient Health Questionnaire (PHQ-9) score score between 5-14
4. Have access to a broadband internet connection
5. Are able to read and speak English

Exclusion Criteria:

Women who:

1. Have visual, hearing, voice, or motor impairment that would prevent completion of study procedures
2. Are diagnosed with a psychotic disorder, bipolar disorder, dissociative disorder, substance use disorder or other diagnosis using the Mini International Neuropsychiatric Interview (MINI) for which participation in this trial is either inappropriate or dangerous
3. Are currently receiving treatment (medication or psychotherapy), or have an intention to resume antidepressant medication after delivery (i.e., women who discontinued their medication during pregnancy)
4. Are suicidal (i.e., have ideation, plan, and intent)