Participant Information Leaflet

You are invited to take part in a research study. Before you decide, please read the following carefully, talk to others about it if you wish, and ask us anything that is not clear. Take your time to decide whether you want to take part.

This study is organised by the University of Warwick, in partnership with Monash University Malaysia, and funded by the Monash Warwick Alliance Research Activation Fund. Dr Sagar Jilka (University of Warwick) is the Chief Investigator for the Warwick arm.

Young people are more likely than older adults to experience anxiety and depression, and how we use our phones - time on social media, or phone use close to bedtime - may be linked to how we feel. Using an app called DataDoc, this study looks at whether everyday patterns of smartphone use are related to changes in wellbeing over 6 months. A parallel study runs at Monash University Malaysia so findings can be compared between the two countries.

If you take part, you will be asked to:

• Join online and save your code. You read this leaflet and consent on the study website (study.sagarjilka.com). You are then shown a unique participant code (like DD-XXXXXX) - keep it safe: you enter it once in the app to activate your participation, and it is how your data is linked without using your name.
• Install the DataDoc app (Android only). It passively records which apps you use and for how long, to work out measures such as your phone use in the 90 minutes before bed and your share of time on apps such as social media, entertainment and messaging, and to show you your own usage summaries. It does not access the content of your messages, calls, browsing history, contacts, or location.
• Optionally connect your health data - if you choose to, the app reads only your sleep, step count and exercise sessions (nothing else). The study works without this.
• Complete two short questionnaires (the PHQ-9 and the WHO-5 Well-Being Index) once a fortnight in the app - about 2-5 minutes together.
• Take part for 6 months. There are no visits, interviews or focus groups - everything happens through the app, and nothing is audio or video recorded.

When you first set up the app we also ask a short set of one-off questions about you (age, gender, ethnicity, education, employment, shift work, living and relationship situation, sleep timing, and whether you have ever been diagnosed with or treated for depression or anxiety). These help us describe who took part; you can answer "prefer not to say" to any of them, and you only answer them once.

No - taking part is entirely voluntary, and choosing not to (or withdrawing later) will not affect you or your studies or work in any way. To withdraw at any time, just delete your account in the app (see "What if I don't want to carry on?" below).

You won't receive personalised feedback or a diagnosis, but you will contribute to research that could help services and universities better understand and support young people's mental health, and build the evidence base for using everyday smartphone data - rather than more invasive methods - to understand wellbeing.

The main risks are small: some people may find fortnightly mood questions slightly uncomfortable (you can skip any question or take a break), and there is a privacy consideration because the app records phone-use patterns. We keep that low - the app records only how long apps are used and when, never content; your data is linked to a code, not your name; and it is held on a secure, encrypted, access-controlled University-approved system (see "confidential" below).

What happens with my questionnaire answers?

The PHQ-9 and WHO-5 are used here as research measures, not a personal test or diagnosis - you are not shown a score or assessment. There is one exception, to help you: if your answers suggest you may be having a harder time, the app immediately shows you free support services (such as the University of Warwick Student Wellbeing & Mental Health Team, Samaritans on 116 123, Shout by texting SHOUT to 85258, and NHS 111), and if there is any indication of risk to yourself it also shows emergency options including calling 999.

This signposting is automatic and immediate. The research team does not monitor or act on your questionnaire answers or scores, so please contact the services shown directly, or call 999 in an emergency, rather than waiting to hear from us. The team is overseen by a consultant psychiatrist (Prof Swaran Singh). The only situation in which we would break confidentiality is if you contact us directly (for example, by email) to tell us that you, or someone else, is at serious risk of harm - never on the basis of a questionnaire answer.

As a thank-you for your time, you receive £2.50 for each fortnightly check-in you complete (one in the first week of the month, one between weeks two and three) - so up to £5 a month and up to £30 over the 6 months, paid as an Edenred shopping voucher, the University's preferred method. Your voucher is arranged at the end of each month based on the check-ins you completed. A member of the project administration team arranges it by email, so they will hold your name and email for this purpose. Vouchers can be spent at a range of approved retailers.

Yes. In short:

• At enrolment you are given a unique participant code. Your research data is linked to this code, not your name. The link between your code and your identifying information (your email) is stored separately and securely, and is accessible only to the Chief Investigator (Dr Sagar Jilka) and named Research Assistant (Nadia Alam).
• Because your questionnaire responses relate to mental health, they are 'special category' data and are given extra protection - stored on an encrypted, access-controlled University-approved server, accessible only to named team members.
• Only anonymised, aggregated data (with no code, name or other identifier) is ever shared with our Monash University Malaysia collaborators, to compare UK and Malaysian findings, under a formal data sharing agreement between the two universities.
• There is one limit to confidentiality: if you tell us directly (e.g. by email) that you, or someone else, is at serious risk of harm, we have a duty of care to act, which may mean contacting emergency services, even without your consent. This never comes from your questionnaire answers, which we do not monitor.

The University of Warwick is the data controller and will use your data only as needed to conduct and analyse the research, in line with data protection law. We keep information that could identify you (your email, and the key linking your code to you) only while you are taking part and until your final voucher is paid. At that point the link is permanently destroyed and your data becomes anonymous - it carries only your participant code, and no one, including the research team, can trace it back to you. The whole dataset is fully anonymous once the last participant's voucher is paid. The anonymous dataset is kept for at least 10 years, in line with the University's research data policy.

You can ask us to withdraw your data up until the end of your own 6-month collection period; after that it has been anonymised and combined with others' data, so an individual contribution can no longer be identified or removed. Your rights to access or change your information are limited, as we need to manage it in specific ways for the research to be reliable.

With your separate consent, your anonymised data may also be used in future, ethically-approved research, and by students undertaking supervised research projects within the University - in every case only data from which you cannot be identified. For more, see the University of Warwick Research Privacy Notice, or contact the Legal and Compliance Team at [email protected].

You can withdraw at any time, without giving a reason and with no effect on you, your studies or your work - just delete your account in the app (Settings → "Delete my account & leave the study"), which stops data collection and removes the data held about you. After the 6-month period your data will have been anonymised and combined for analysis, so from that point it can no longer be individually removed.

Findings will be written up for academic publication and shared through conference presentations, infographic summaries for university wellbeing services, and public engagement. A plain-language summary of the overall (group-level) findings will be put on the University of Warwick's study pages once the study concludes - only group-level findings are ever shared, never individual results. We do not keep contact details to send results.

This study has been reviewed by the University of Warwick's Biomedical & Scientific Research Ethics Committee (BSREC): [reference number tbc].

Study team: Dr Sagar Jilka, Chief Investigator ([email protected]); Nadia Alam, Research Assistant ([email protected]), Warwick Medical School.

Complaints (someone independent of the study): Head of Research Governance, University House, University of Warwick, Coventry CV4 8UW - [email protected], 02476 575733. For a complaint about how your personal data has been handled, contact the Data Protection Officer ([email protected]); you may also complain to the Information Commissioner's Office (ICO).

Thank you for taking the time to read this Participant Information Leaflet.