This pilot randomized controlled trial aims to evaluate the feasibility, acceptability, and preliminary effects of a culturally adapted, one-day online Cognitive Behavioral Therapy (CBT)-based group workshop for women with postpartum depression in Türkiye. The intervention was adapted from a validated model developed in Ontario, Canada, using Bernal's cultural adaptation framework.

Participants will be randomly assigned in a 1:1 ratio to either a workshop group, who will receive the one-day online CBT-based workshop within the first month after enrollment, or a control group who will continue to receive usual postpartum care throughout the study period. Data will be collected at baseline and at the 3-month follow-up using the Edinburgh Postnatal Depression Scale (EPDS), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), the Frequency of Actions and Thoughts Scale (FATS), and the TÜRBAD Satisfaction Questionnaire (TÜRBAD-SQ).

The study will assess feasibility indicators including recruitment, randomization procedures, completion of study questionnaires, retention through the 3-month follow-up, and adherence to the one-day workshop. Acceptability and preliminary changes in depressive, anxiety, and cognitive-behavioral outcomes will also be explored.

This pilot trial represents the first culturally adapted, one-day online CBT-based group intervention for postpartum depression in Türkiye and will inform the design of a future large-scale randomized controlled trial.

Postpartum depression (PPD) is a major public health concern affecting approximately one in five women worldwide and nearly one in five mothers in Türkiye. Despite its high prevalence, access to brief, evidence-based, and scalable psychological interventions remains limited, particularly in low- and middle-income settings. Untreated PPD increases the risk of chronic depression, impaired mother-infant bonding, and adverse emotional, behavioral, and developmental outcomes in children.

Cognitive Behavioral Therapy (CBT) is recommended as a first-line treatment for mild to moderate depression in the perinatal period; however, conventional CBT typically requires 12-15 weekly sessions, which can be difficult for new mothers due to caregiving demands, time limitations, and social isolation. Group-based interventions promote normalization and peer support but remain relatively inaccessible. Therefore, brief, structured, and scalable models are urgently needed.

A one-day CBT-based group workshop developed in Ontario, Canada has demonstrated feasibility, acceptability, and effectiveness in reducing postpartum depression. This study represents one of the first efforts to culturally adapt and evaluate this workshop for women in Türkiye. The adaptation followed Bernal's cultural adaptation framework to ensure conceptual, linguistic, and contextual relevance. All intervention materials were refined and finalized for pilot implementation following this adaptation phase.

This pilot randomized controlled trial aims to evaluate the feasibility, acceptability, and preliminary effectiveness of the culturally adapted one-day online CBT-based workshop among women with postpartum depressive symptoms in Türkiye. Sixty participants aged 18-45 years within the first postpartum year and with an Edinburgh Postnatal Depression Scale (EPDS) score ≥10 will be randomly assigned (1:1) to one of two groups: (1) a workshop group, who will receive the one-day online CBT-based workshop within the first month after enrollment; or (2) a control group, who will continue to receive usual postpartum care.

Eligible participants will be women aged 18-45 years who are within one year postpartum, have an EPDS score ≥10, are literate in Turkish, and have access to a stable internet connection. Exclusion criteria include current psychotic, bipolar, organic mental, or substance use disorders; a severe depressive episode requiring immediate clinical intervention; active suicidal ideation or intent; serious medical or neurological conditions that impair participation; or having an infant with a life-threatening congenital condition.

Assessments will be administered at baseline and at three months and will include the EPDS, Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), Frequency of Actions and Thoughts Scale (FATS), and the TÜRBAD Satisfaction Questionnaire (TÜRBAD-SQ). Although some Turkish validation studies suggest an EPDS cut-off of 12-13, a threshold of 10 was selected to align with international postpartum mental health research and to capture clinically relevant depressive symptoms.

Participants will be recruited through Marmara University clinical settings and community outreach channels.

Data collection and randomization will be conducted using REDCap (Research Electronic Data Capture) to ensure secure data management and methodological rigor. Findings from this pilot study will inform refinement of the intervention procedures, feasibility targets, and outcome measures, and will guide the development of a future large-scale randomized controlled trial.

Inclusion Criteria:

• Female participants aged 18-45 years
• Having an infant aged 1-12 months
• Presence of clinically relevant postpartum depressive symptoms (EPDS ≥10)
• Literate in Turkish (able to read and write)
• Access to a stable internet connection
• Willing and able to provide informed consent

Exclusion Criteria:

• Current psychotic, bipolar, organic mental, or substance use disorder
• Severe depressive episode or impaired judgment due to psychiatric illness
• Active suicidal ideation or intent
• Medical or neurological condition preventing participation (e.g., dementia, intellectual disability, severe hearing or visual impairment)
• Infant with a life-threatening congenital disorder

Individual participant data will not be shared due to institutional and ethical restrictions. Aggregate (summary) results will be made available in related publications and presentations.

This is an open-label pilot randomized controlled trial. Participants and facilitators cannot be blinded due to the nature of the behavioral intervention. However, outcome assessors and data analysts will remain blinded to group assignment to reduce potential assessment and analysis bias.