Be a mom (a web-based cognitive-behavioral intervention) is being tested in another trial as a preventive intervention in the postpartum period (NCT03024645). However, given its content and the focus on developing and strengthening psychological resources, it is important to understand if Be a Mom is also effective in promoting maternal mental health of postpartum women who are not at risk of developing postpartum depression. Thus, the main goal of this research is to apply and evaluate Be a Mom for the promotion of mental health, in terms of its efficacy, acceptability and feasibility (user's adherence, dropout), user's satisfaction and cost-effectiveness.

The RCT will be a two-arm trial. Women with a child aged up to 3 months old will be enrolled in the study. A minimum number of 1000 women will be enrolled in the study. After agreeing to participate in the study, the women will be screened for the absence of risk factors for PPD (PDPI-R < 5.5). In case of a negative screen, women will be randomly assigned to one of two conditions: the intervention (Be a Mom program) or the control condition. The sample will be recruited online.

Participation in this study will last 15 months. The Be a Mom program will last 5 weeks. Participants in both conditions will be invited via email to complete baseline, post-intervention and follow-up assessments (4-months and 12-months after post-intervention). Assessments will include self-report questionnaires to assess several indicators (e.g., positive mental health, quality of life, marital satisfaction, depressive and anxiety symptoms, maternal self-efficacy), mechanisms that may be involved in the treatment response (e.g., self-compassion, emotional regulation), user's acceptability and satisfaction and cost-effectiveness.

In the present study, a web-based intervention to promote women's mental health in the transition to motherhood (the Be a Mom program) will be tested. The design and content development of the Be a Mom program was conducted through a formative evaluation process.

The transition to motherhood is a widely studied period that is characterized as demanding for mothers, and that entails an adjustment to lifestyle changes and new responsibilities. There is extensive research suggesting that this period is a time of increased risk for psychological problems, such as postpartum depression. In turn, this can lead to numerous negative consequences to the mother and the child's development.

Even women who are not at an immediate risk of developing postpartum depression face numerous challenges and concerns that may place them in a vulnerable position (e.g., health needs, infant care, conflict with partner, changes in marital/social relationships, transitioning back to work). Despite this, research on the transition to motherhood has largely focused on women at risk or presenting mental illness, overlooking all women in the postpartum period and their positive mental health.

Evidence shows that positive mental health over time functions as a resilience resource and protects against both physical and mental illness. There is also evidence suggesting that the lack of positive mental health may also make individuals more vulnerable to future adversities. This implies that the promotion of positive mental health should be an additional goal in public and mental health care that complements the treatment of psychopathology.

Be a Mom is self-guided web-based intervention grounded on CBT principles that also includes recent developments in acceptance and commitment based-therapies, specifically for the perinatal context. This program focuses on the development and enhancement of psychological resources such as self-compassion and psychological flexibility and an increase of mental health literacy. Be a Mom has a modular set-up that is updated weekly, with each module addressing one or two specific thematic contents (Changes and reorganizations during the transition to parenthood; Emotional diversity; Cognitions; Relationship with others [social support and communication]; Couple relationship; Signs and symptoms of depression and help-seeking). In each module, participants will be provided with both psychoeducational content and therapeutic strategies. Informational material will be given in text format, combined with audio, video and/or animations. The Be a Mom program will also include interactive tools and feedback tools to support learning.

The main goal of the research is to apply and evaluate Be a Mom for the promotion of maternal mental health, in terms of its efficacy, acceptability and feasibility (user's adherence, dropout), user's satisfaction and cost-effectiveness. The efficacy of the program will be assessed considering two indicators: a) increase in levels of positive mental health at post-intervention and throughout the first postpartum year; and b) post-intervention and follow-up improvements in mother's psychosocial adjustment indicators (e.g., depressive and anxiety symptoms, self-empowerment, quality of life, maternal self-efficacy, marital satisfaction). The present study will also aim to investigate the mechanisms explaining the treatment response (e.g., self-compassion, emotion regulation).

The research design of the trial followed the methodological recommendations for the development and evaluation of web-based interventions. A pilot study was conducted in order to assess user's satisfaction and acceptability of the structure and content of the Be a Mom program and carry out appropriate adjustments. The results allowed to identify and implement modifications and the final version of Be a Mom was conducted, allowing for further efficacy studies.

The RCT will be a two-arm prevention trial, conducted in low-risk women (PDPI-R < 5.5). The intervention condition (the Be a Mom program) will be compared with a control condition (Treatment as Usual). The sample will include women who delivered a healthy baby in the early postpartum period (up to 3 months postpartum). Women will be recruited online through social media and websites and forums focused on motherhood. A minimum number of 150 women per condition will be required (N=300). Accounting for the proportion of high-risk and low-risk women and the 50% of attrition rate over time, an anticipated sample of 1000 women will be enrolled in the study.

Women who demonstrate interest in the study will be informed of the study goals, the structure and arms of the research and the researchers' and participants' roles. Women who agree to participate in the study will give their informed consent. All ethical requirements for research with humans are guaranteed. Women will be screened for the presence of risk factors for PPD. In case of presence of risk factors, women's participation in the study will end. In case of not presenting risk factors for PPD (PDPI-R < 5.5), women be randomly assigned (blocked randomization, with allocation concealment) to one of the conditions: the intervention (Be a Mom program) or the control condition.

A researcher (licensed psychologist) will contact women in the intervention condition, aiming to explain the program's structure and provide assistance during the course of the study.

Participation in the study will last 15 months. The Be a Mom program will last 5 weeks. Participants in both conditions will be invited via email to complete baseline, post-intervention and follow-up (4-months and 12-months after post-intervention) assessments. Assessments will include self-report questionnaires to assess several indicators (e.g., mental health, quality of life, marital satisfaction, depressive and anxiety symptoms, maternal self-efficacy), mechanisms that may be involved in the treatment response (e.g., self-compassion, emotional regulation), user's acceptability and satisfaction and cost-effectiveness.

Inclusion Criteria:

• Having 18 years or more;
• Being female;
• Having had a live healthy birth in the last 3 months, with both woman and the child discharged from hospital;
• Internet access at home.
• Absence of risk factors for Postpartum Depression (PDPI-R < 5.5).

Exclusion Criteria:

• Current diagnosis of serious mental health condition (e.g., substance abuse, bipolar disorder);
• Currently receiving treatment for depressive symptoms, including antidepressant medication or psychotherapy;
• Language difficulties that impede comprehension/reading-writing;

Single-blind - the investigator is unaware of the intervention assignment