The goal of this study is to investigate whether pregnant people at risk of, or currently suffering from antenatal depression, find it acceptable to use the 'HappyMums' mobile application during their pregnancy. This app will collect data relevant to their mental health passively and through active engagement from the user. After the study is complete, these data will be put together to determine if such data types could be used in future to help predict and identify antenatal depression, and aid better treatment decisions.

HappyMums aims to develop a digital platform (smartphone app), and investigate whether data collected by a mobile app can be used to help learn more about mental health symptoms in pregnant women and birthing people at risk of depression in pregnancy.

This study aims to investigate the acceptability and usability of the HappyMums App. Following data collection, data will be aggregated to generate statistical models, with the aim of testing their predictive ability for antenatal depression trajectories.

The application will collect and integrate heterogenous data and will also allow an improvement of lifestyle attitudes, the maintenance of wellbeing in pregnancy, and the continuous monitoring of treatment efficacy. HM will therefore contribute to reducing the stigma by empowering mothers and birthing parents to monitor and master their mental health.

The study objective is to actively and passively gather data relevant to perinatal mental health, via a mobile application, which will be used to retrospectively develop an algorithm capable of identifying mental health trajectories in at-risk women/birthing people. The app will include game-like activities, access to an antenatal wellbeing course and space for pregnancy- and health-related data logging and monitoring. It will also utilise smartphone sensors to collect passive data types such as GPS, phone usage and step counts. This study will test the use of such mobile applications for patient mental health monitoring, and will also collect traditional research data such as biological samples and standardised questionnaires to be used as comparators to app-derived data.

Participants: Participants will be pregnant people either currently experiencing depressive symptoms, or who meet criteria for at least one risk factor for antenatal depression, previously identified from the literature, such as pregnancy complications or lack of social support. They will be recruited from 13 weeks' gestation to 28 weeks' gestation.

Recruitment: Recruitment will be conducted through self-referral, social media and online advertisement, and poster/flyer advertising in spaces and publications relevant to pregnant people, such as antenatal and health clinics, antenatal education spaces, children and family centres and newsletters.

Measures and Outcomes: Models will be generated to determine the ability of passively and actively app-collected data to predict antenatal depression symptoms through pregnancy, and how this compares to traditional measures such as standardised mental health questionnaires: Edinburgh Postnatal Depression Scale (EPDS), Generalised Anxiety Disorder Assessment (GAD-7) and Patient Health Questionnaire (PHQ-9).

For further cohort characterisation and to determine the influence of risk factors, other measures will also be collected and tested in the model: Mini International Neuropsychiatric Interview (subset only), Childhood Trauma Questionnaire (subset only), Adult Attachment Questionnaire, Life Events, Composite Abuse Scale, Maternal Antenatal Attachment Scale (subset only), Perceived Stress Scale (subset only), Multidimensional Scale of Perceived Social Support (subset only), Couple Satisfaction Index (subset only) and Postpartum Bonding Questionnaire (subset only).

Inclusion Criteria:

• Pregnant people, aged 18 or older and up to 28 weeks' gestation.
• Satisfactory understanding of English/national language of host country, in order to give fully informed consent.
• Either suffering with depressive symptoms currently, or who have at least one risk factor for antenatal depression.
• Owning a smartphone capable of downloading and running HappyMums application

Exclusion Criteria:

• Inability to give informed consent.

The study will consist of pregnant participants, up to 28 weeks' gestation, who have at least one risk factor for antenatal depression, or current depressive symptoms.