Welcome to HOUDINI-BD

Bipolar disorder is a common mental health condition characterized by significant shifts in mood, energy, and sleep patterns during recurring episodes, interspersed with periods of relative stability. One of the main challenges in care is that changes in mood, energy, and sleep often begin between clinic visits, while patients struggle to recognise and report their symptoms. This makes new episodes difficult to detect and address early, leading to worse outcomes.

The "Blood Sugar" Analogy
At present, there is no simple, objective test for monitoring bipolar disorder—nothing comparable to the finger-prick blood sugar test used in diabetes care. As a result, early warning signs can be missed, thus limiting opportunities for timely support or intervention.

A Modern Solution
Smart wristbands (such as smartwatches) offer a potential way to bridge this gap. By tracking sleep and activity levels continuously and with minimal effort, they provide an ongoing view of everyday patterns. Subtle changes in these rhythms may signal that a person’s mental state is beginning to shift.

The HOUDINI-BD Mission
HOUDINI-BD will be exploring whether this type of technology can be a practical and reliable way to support the monitoring of bipolar disorder in daily life. The study is observational and does not provide diagnosis or treatment. We focus on two main areas:

Who can take part?

Below is an overview of the study procedures and how we handle your data. Please refer to the downloadable Participant Information Sheet for further details.

Please read carefully before deciding to take part. If you have any questions, feel free to contact the research team.

What can I expect if I take part?

If you are eligible after screening and choose to participate, we will arrange a baseline appointment with you at one of the West London NHS Trust (WLT) Community Adult & Recovery Mental Health Services. This visit will take approximately 70–80 minutes; you will be able to take breaks at any point to ensure you stay comfortable. During the baseline appointment, you will have a chance to ask any questions you may have about the study. If you decide to take part, we will ask you to sign a consent form and we will collect some information about your mental health history and demographics (e.g. age, sex, occupation). You will also complete a brief speech task (5 minutes) where you will be asked to speak about neutral topics. This will be audio-recorded using a secure system. During the baseline appointment, will then provide you with a smart wristband (further details below) to wear on your nondominant wrist over the next 12 months in your daily life. We will periodically send you (over email or text message) reminders to wear and recharge the wristband. Following the baseline appointment, you will receive your first £30.00 payment.

During the baseline appointment, we will provide you with a unique login and a link to download the MindCraft app from the App Store or Play Store (further details below). This app runs in the background to track activity, such as steps, ambient light, and background noise levels. While more data helps us better understand bipolar disorder, you remain in control and can turn these tracking options on or off at any time.

For the first four weeks of the study, the MindCraft app will also prompt you twice daily to answer a few short questions about your mood and sleep. During this same 4-week period, you will receive brief (3–5 minute) weekly phone calls from an AI Voice Assistant (further details below). This assistant will ask about your wellbeing and health to help us collect and analyze speech samples securely.

After these first four weeks, the daily surveys on MindCraft and the AI Voice Assistannt phone calls will stop. For the remainder of the 12-month study, you will simply continue wearing the wristband and allow the MindCraft app to collect background data based on the settings you have chosen (which you can update at any point). You can contact the research team at any point if you have questions or need help with any of the technology.

To see how you are getting on, we will meet for four short follow-up appointments (30–40 minutes) every three months, in the same location as the baseline appointment, over the course of the 12-month study. You will receive £30.00 after each appointment (totalling £150.00 over the course of the entire study, including the baseline appointment). If you withdraw from the study before completing it, you will retain any payments given up to that point. During these follow-up appointments, we will download data collected in-between appointments with the wristband. Lastly, you will also complete a brief speech task (5 minutes) similar to the one completed at the baseline appointment. We will use a questionnaire to determine whether any mood episode took place in between assessments or is ongoing and we will ask you about any changes in your medications. During the first follow-up appointment, you will take a survey on your experience with the technology during the first three months of the study. Speech from the speech task and survey on technology experience will be securely recorded for analysis. No other speech data will be recorded during the follow-up appointments.

Below you can find an illustration of the study procedures discussed above (Figure 1) along with more details on the wristband you will be wearing, the MindCraft app, and the AI Voice Assistant.

How will you use and protect my data?

To carry out this research, we will need to use information collected from you while you take part in the study.

What information we will collect
This includes:

• Your name and contact details
• Health and background information, such as the number of past bipolar episodes, current medications, and your answers to questionnaires
• Information collected through the MindCraft app
• Data from the Axivity AX6 wristband
• Audio recordings, including:
  • recordings made during speech tasks at the baseline and follow-up appointments,
  • recordings from the weekly 5-minute phone calls during the first four weeks of the study,
  • recordings of your responses to questions around technology experience at the baseline and follow-up appointments

Who will use this information

• Members of the study team and authorised staff at Imperial College London will use this information to carry out the research.
• Some staff may also check records to make sure the study is being run properly and that contact details are correct.
• People who do not need to know who you are will not see your name or contact details.
• Wherever possible, your data will be labelled with a code number instead of your name.
• Imperial College London is the sponsor of this research and is responsible for keeping your information safe.

How we keep your information safe
We use a range of secure systems and procedures:

• Screening questionnaires are collected using Qualtrics, a system that complies with UK GDPR rules. Data are stored on secure Qualtrics servers and then transferred to Imperial College servers. Once transferred, the data are deleted from Qualtrics. If someone does not meet the study criteria or decides not to take part, their data will be destroyed.
• Personal identifiable information (such as consent forms and contact details) is stored in locked cabinets at the study sites.
• Phone calls between you and the research team (for example, to ask questions or arrange appointments) are not recorded.
• Clinical and background information is stored securely using REDCap, a GDPR-compliant research database.
• Speech recordings are handled securely:
  • In-person recordings are stored using encrypted, HIPAA-compliant software.
  • Automated phone calls use a secure, encrypted system.
  • These systems are designed so that audio data cannot be used for other purposes, including training artificial intelligence systems.
• AX6 wristband data are downloaded during follow-up visits onto an Imperial College-owned laptop and then uploaded to a secure Imperial College server.
• MindCraft app data (such as app use and behaviour data) are sent directly to a secure server located within Imperial College London.

Sharing anonymised data (optional)
You can choose whether or not your anonymised data may be shared publicly by selecting the relevant option on the consent form. If you agree:

• Your data will be shared without any information that identifies you.
• Sharing anonymised data helps make research more transparent and allows other researchers to build on the findings.

To reduce the risk that someone could identify you:

• Time stamps from the AX6 wristband will be shifted slightly, and data will be resampled.
• Information on ethnicity and employment will only be shared in grouped form across all participants.
• Age will be shared in 5-year bands (for example, 21–25 rather than a specific age).
• Location data from your smartphone, if collected through the MindCraft app, will not be shared.
• Voice recordings will not be shared; only anonymised text transcripts may be shared.

Please reach out to us using the contact details below. Alternatively, if you prefer, please leave your contact email and your message in the boxes below and click on 'Send email'. An email will be sent to the research team at the email address below through the GDPR-compliant (General Data Protection Regulation) Formspree service.