This study is a prospective, two-arm parallel cluster randomized controlled trial that will compare the intervention effects of a positive psychology-based intervention package with usual care for postpartum depression.

Postpartum depression is one of the most common conditions affecting women during the perinatal period. It has a profound negative impact on both women's physical and mental health, manifesting in symptoms such as persistent low mood, sleep disturbances, changes in appetite, and a diminished sense of self-worth. In more severe cases, it may even lead to suicidal ideation or self-harm. Furthermore, postpartum depression significantly impairs a mother's caregiving ability, weakening the emotional bond between mother and infant. This disruption in the mother-infant relationship, in turn, can negatively affect the infant's social, emotional, and cognitive development.

Positive Psychology is an emerging subfield of psychology that focuses on the study of human positive emotions, well-being, and optimal adaptation. In contrast to traditional psychology, which primarily addresses mental illness, abnormal behaviors, and negative emotions, Positive Psychology seeks to explore and enhance the ways in which individuals and groups can thrive in areas such as positive emotions, health, and happiness. By focusing on strengths, resilience, and positive interpersonal relationships, Positive Psychology aims to foster well-being rather than merely alleviating psychological distress.

The emphasis on prevention in Positive Psychology aligns closely with the core principles of community-based primary healthcare, which prioritizes early intervention, education, and the promotion of wellness within a population. By focusing on proactive strategies that enhance mental health, Positive Psychology contributes to a broader public health agenda aimed at reducing the burden of mental disorders through early prevention rather than relying solely on treatment after the onset of illness. Therefore, integrating Positive Psychology into primary healthcare settings-particularly in the prevention and management of postpartum depression in women-offers substantial potential benefits.

This study will design a community-based intervention program for postpartum depression, centered on Positive Psychology, within the framework of the primary healthcare system. The program will be developed based on the developmental characteristics and practical needs of women experiencing postpartum depression. A cluster-randomized controlled trial will be employed to evaluate the effectiveness of the intervention. The findings will provide valuable evidence and support for mental health management measures for pregnant and postpartum women in primary healthcare settings, thereby promoting the effective implementation of maternal and child health initiatives.

Inclusion Criteria:

• age ≥18 years;
• women in the early stages of pregnancy;
• adequate cognitive, comprehension, and communication abilities, and voluntary participation in the study.

Exclusion Criteria:

• individuals with severe organic or somatic diseases;
• those with a history of mental illness, substance abuse, or a family history of psychiatric disorders.