Last updated August 22, 2026
Privacy policy and consent for the Kessler 10 app. What the app handles, how it is stored, and what you agree to if you take part in research.
Aust. Psych. Res. Pty Ltd ("we," "us," "our") operates the Kessler 10 mobile application (the "App"). This document explains what information the App handles, how it is stored, and — if you choose to take part in our research — what you are consenting to.
By default, the Kessler 10 app does not collect, transmit, or share any personal data — everything is stored only on your device. The one exception is an optional research feature, described below. Nothing leaves your device unless you join it, which you do by signing in with Apple from the Research tab.
This app is not a crisis service and cannot respond in an emergency. If you are having thoughts of harming yourself, please contact a crisis support line or emergency services in your area right away.
The App is a screening and research tool. It does not diagnose any condition, provide treatment, or offer personalized medical or mental health advice. A score is not a diagnosis. If you are finding things difficult, please consider speaking to a doctor, a mental health professional, or someone you trust.
We do not collect, and the App does not transmit off your device, unless you explicitly opt in to the research feature described below:
To provide its core features, the App stores the following locally, on your device only, using Apple's standard on-device storage (UserDefaults):
This data never leaves your device unless you opt in to the research feature below. It is not visible to us, and we have no way to access it. If you delete the App, this data is deleted along with it.
The App includes an opt-in research feature, currently built as a prototype and pending ethics committee approval. Nothing is collected unless you join, which you do by signing in with Apple from the App's Research tab after reading what taking part involves. The App works exactly the same way whether you take part or not.
We invite you to participate in our research. If you opt in, we collect only:
We do not collect your answers to the individual questions — only the total score they produce. We do not collect your name, email address, phone number, device identifier, location, or any other identifying information. We do not receive or store your Apple ID either: it is used on your own device to work out your participant ID, and is never sent to us.
Assessments already completed on your device when you join are contributed as part of taking part. This is not a separate question and there is no option to leave them out: joining the research contributes the assessment history the App already holds, along with everything you complete afterwards. Each one is submitted with its own original date, so the research data reflects when the assessment was actually completed.
Your assessments remain in your own history in the App either way. If you would prefer earlier ones were not contributed, delete them from your history before you join, or withdraw and delete your data afterwards.
Taking part requires you to sign in with Apple, once, from the Research tab. Signing in is also how you give consent: the Research tab sets out what taking part involves, and the sign-in button beneath it says that tapping it means you agree to those terms. There is no separate switch to turn on. If you close Apple's prompt without confirming, nothing is recorded and you have not joined.
There is nothing to type. Your phone is already signed in to an Apple ID, and Apple simply asks you to confirm. We request no name and no email address from Apple — not even a private relay address — so none is given to us.
What Apple provides the App with is a long identifier that is unique to you and is the same across every app we publish. Your phone converts that identifier into your participant ID by combining it with a fixed secret built into the App and passing the result through a one-way cryptographic function (SHA-256). Only the result is stored or transmitted. The Apple identifier itself never leaves your device, and the conversion cannot be run backwards to recover it.
The purpose of the ID is to link your own records to each other over time, so that repeated assessments from the same participant can be analysed together.
Because the ID no longer depends on this particular installation of the App, it stays the same if you delete and reinstall, and it is the same on any other device signed in to the same Apple ID. This is deliberate: it means a participant who takes a break and comes back is counted as one participant rather than two.
The same participant ID is used by our other research apps, Cold Water Swimming Therapy and the Food and Lifestyle Scale. If you take part through more than one of them, those records carry the same ID and can be analysed together as belonging to one participant. If you would prefer that not to happen, take part through one app only.
Your records are pseudonymous: they are linked to each other, but not to your name or your contact details. We have no way of knowing who you are and no way of contacting you. We hold neither your Apple identifier nor any means of obtaining it from Apple, so we cannot work backwards from a participant ID to a person.
Because we cannot identify you, we cannot contact you, follow up with you, or respond to what your scores show. No one is monitoring the research data for individual participants in difficulty, and taking part in the research is not a way of asking for help or being noticed.
This is a deliberate design choice that protects your privacy, but it has a real consequence: if you are struggling, the research will not reach you. The App shows guidance on its results screen for that reason, and please treat it seriously. Support comes from a doctor, a mental health professional, someone you trust, or a crisis support line — not from this research.
We only use the data to create norms, so that you can compare your own scores with other participants from Australia and the United States.
Each participant counts once in those norms, represented by their most recent assessment, so that someone who assesses themselves often does not carry more weight in the figures than someone who does it once.
Your own records are excluded from the group you are compared against, so the comparison is genuinely with other participants rather than partly with yourself. This continues to apply after you withdraw: if you chose to leave your records in the dataset, the App still identifies them so they can be left out of your own comparison, which means it sends your participant ID when loading these figures. Nothing else is sent, and this only happens if you have contributed records — if you have never opted in, nothing leaves your device at any point. Group statistics are only displayed once a country group reaches at least 10 other participants, so that no individual can be inferred from a small sample. This means the figures shown to two participants in the same country differ very slightly, since each is compared against everyone except themselves.
Only the most recent 12 months of data is used for the norms shown in the App.
Findings from this research may be published in academic literature, presented to researchers or government agencies, and included in a book sold commercially. Aggregate results and norms may also be licensed or sold to third parties.
Only grouped statistics are ever published, licensed, or shared. Your individual records are never sold, never shared with advertisers, and never used for any purpose other than this research.
You can join or withdraw at any time. Withdrawing is a single button in the Research tab, and it asks what should happen to the records you have already contributed:
Delete my data. Your records are removed from the research database entirely. The norms are recalculated from whatever data exists at the time, so once your records are deleted they no longer contribute to the norms.
Your participant ID is not replaced afterwards, because it cannot be — signing in with Apple again produces the same ID. If you later opt back in, you return under the ID you had before. Your deleted records are gone from the research database either way, but we would rather say plainly that this is not the clean break a newly generated ID would have given you: a copy of the data exported for analysis before you withdrew may still carry that ID.
Save my data. No further data is collected, but the records you have already contributed stay in the research database, because you have chosen to let them continue to count. Your participant ID stays the same, so if you ever opt back in you are recognised as the same participant rather than appearing as a new one.
Either way, no further records are sent, and your own history stays on your phone.
You can withdraw at any time. There is no deadline, but there is one point at which the choice is made: deleting your contributed records is offered when you withdraw, and not as a separate action afterwards. If you withdraw and choose to save your records, and later decide you would rather they were removed, you would need to take part again and then withdraw a second time, choosing to delete. If you would prefer nothing of yours to remain, choose "Delete my data" at the point of withdrawing.
Records you leave in the database are used exactly as described elsewhere in this document, and no differently to any other participant's: they are kept under the same ten-year retention period, they continue to contribute to the norms shown in the App as one participant represented by their most recent record, and they may be included in published group findings.
They are also indistinguishable, within the database itself, from the records of someone still actively taking part. Your consent to leave them there is recorded in the App at the moment you make the choice, rather than being stored alongside the records. We have chosen not to write a "withdrawn" marker to the database, because doing so would require giving the App a way to modify stored records, which it deliberately does not have.
If you would prefer no trace of your participation to remain, choose "Delete my data" at the moment you withdraw.
Research records are kept for ten years from the date they are submitted, and are then permanently destroyed.
Older records remain part of the research dataset for analysis during the retention period, but only the most recent 12 months is displayed in the App.
You have the opportunity to delete your records when you withdraw, as described above.
The data custodian for this research is James Anderson, on behalf of Aust. Psych. Res. Pty Ltd. Questions about the research, or requests relating to your data, can be directed to the contact address at the end of this document.
Research data is stored in a database hosted by Supabase Inc. on Amazon Web Services infrastructure in the Asia Pacific (Sydney) region, ap-southeast-2. Supabase Inc. is a United States–incorporated company, although the data itself is held in Australia.
The data is encrypted in transit and at rest. Access to the raw records is restricted: the App itself can only read grouped, aggregate statistics through a restricted database function, and cannot retrieve individual participants' records — including your own. The grouping, the exclusion of your own records, and the minimum group size are all applied inside the database before anything is sent to the App, so no individual record is ever transmitted to a device.
For analysis, data is exported from the research database as a data file and imported into SPSS statistical software. Working copies are held offline on an external hard drive encrypted with FileVault, the macOS full-disk encryption system, and accessed from an iMac running macOS. The drive is kept in a secured location.
Exported copies contain the same information described above and no more — no name, email address, phone number, or other identifying information is added at any stage. Because the participant ID is shared across our research apps, an export may be combined with an export from another of those apps to analyse the same participant's records together. They are destroyed on the same ten-year schedule as the records themselves, counted from the date the data was created rather than the date it was exported.
This feature is not active for all users at all times — as a prototype pending ethics approval, it may be turned off entirely at points, in which case no data is transmitted even if you have opted in.
The Kessler Psychological Distress Scale (K10) was developed by Ronald C. Kessler and colleagues. It is reproduced in this App as published, and is used here for screening and research purposes only. The scoring bands follow Andrews and Slade (2001). Full references are listed in the App.
The App is intended for users aged 18 and over and is not directed at children. We do not knowingly collect any information from anyone under 18. The research feature described above is intended only for adult participants; if you are under 18, please do not opt in.
If this Privacy Policy and Consent document changes, the updated version will be posted here with a revised "Last updated" date.
If you have questions about this Privacy Policy and Consent document, or about the research, contact us at: