The goal of this study is to develop a postpartum depression (PND) Risk index using the UK Biobank dataset, and to validate the risk index in Hong Kong postpartum women.

Participating Hong Kong postpartum women will wear an actigraphy (GENEActive) for 14 consecutive days.

Inclusion Criteria

• Mothers who are at least 18 years of age and are within 6 months of giving birth.
• Participants must be capable of reading Traditional Chinese, Mandarin, or English, to ensure they can provide informed consent and complete the required study documentation.

Exclusion Criteria

• Individuals with specific conditions that might interfere with the measurement of sleep patterns related to mood will be excluded. This includes mothers diagnosed with sleep apnea or those who use CPAP machines.
• To reduce physiological noise in the data, women working permanent night shifts or those with severe medical complications, such as pre-eclampsia requiring ongoing medication, will also be excluded

Only female will be eligible to participate this study.

Postpartum mothers who gave birth within 6 months and reside in Hong Kong

To comply with the IRB for this study, the data will not be shared with other researchers. All collected data will be stored securely for 5 years following study completion, in accordance with institutional research data management policies. Access to the Qualtrics survey responses will be strictly limited to the principal investigator, co-investigators and research assistants. Data will be stored in password-protected files on encrypted servers, and all identifying information will be removed during data analysis and reporting. After the 5-year retention period, all data will be permanently deleted by overriding each file.