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How does cannabis use affect the lives of adults with and without ADHD? Help us find out

We need volunteers for our research into how the effects of cannabis on frequent users differ between people with and without ADHD.

Millions of people use cannabis, and it can have different effects from person to person and over time. We know that cannabis use impacts people's mood, attention, and daily experiences, but there has been very little research into whether these effects are different for adults with ADHD.

People who are diagnosed with attention-deficit/hyperactivity disorder (ADHD) are more likely to use cannabis compared to people without ADHD. Some research suggests that cannabis may help people with ADHD cope with their symptoms. However, other research has found that it may worsen symptoms.

We hope that this study (the Cannabis Assessment and Psychological Tracking Using Real-time Evaluations (CAPTURE) study) will tell us more about the effects of cannabis among people who regularly use cannabis and see whether these effects change across time, and between groups with and without ADHD.

Take part in this research study

This study involves two phases. We are recruiting until September 2027.

What you'll do

First phase: 'Baseline'

You will meet with one of our researchers, who will ask you some questions about your:

  • age, sex at birth, gender and ethnicity
  • region of the UK you live in
  • occupation
  • cannabis use
  • symptoms of ADHD
  • mental wellbeing

Second phase: 'Testing'

In this phase, our researchers will guide you to download and install an app on your smartphone. Our app will send you daily notifications to complete a short survey, 5 times per day, for 21 days. We estimate that you will spend approximately 5 minutes per day taking part.

The surveys will ask you about your cannabis use, mood, attention, memory, activity levels, and ADHD symptoms. You will never be notified before 9am or after 10pm.

We will work with your schedule and can be flexible if this changes during the study. We aim to make participating in our research as easy as possible and never expect you to change your daily routines to take part.

Eligibility

To take part in this study, you must:

  • be aged 18 years old or older
  • have a diagnosis of ADHD that has been confirmed by a healthcare professional (e.g., clinical psychologist, educational psychologist, psychiatrist) if you are applying to be in the ADHD group.
  • use cannabis regularly (either prescribed through medical routes or recreationally)
  • be based in the UK and fluent in English
  • have access to Wi-Fi or mobile data and a smartphone, and be able to use apps efficiently
  • not be diagnosed with any serious psychological or neurological disorders that may impair your ability to take part in the study
  • not currently receiving treatment, or seeking treatment, for a substance use disorder, including cannabis use disorder and alcohol use disorder
  • not be pregnant or trying to get pregnant

What you'll get

You will be reimbursed between £25 to £62, depending on how many of your daily surveys you complete.

You can also have an optional debrief session, where you can learn about your responses and how they changed over time, including how cannabis affected you during the study.

Ethical approval

This study has been reviewed and approved by the Biomedical Research Ethics Committee at the University of Bath (reference number 14266-21379)

Your data

All of your data will be anonymised and held by the study investigators, and will be securely stored on an encrypted password-protected electronic computer drive at the University of Bath.

Your participation will remain confidential at all times. Admission of previous drug use is not against the law and therefore, participants will not be reported to any authorities for this.

Results from this project will inform the lead researcher’s PhD thesis. You would not be identified in any way. If you would like a copy of the final paper after the project has been completed, you may request this.

If you decide you no longer want to participate at any time during the study, you can withdraw your participation by emailing CAPTUREstudy@bath.ac.uk

Find out more about how your data will be processed and protected.

Join this research study

If you are interested in taking part in this research study, or have any questions about it, please contact us.