Information Sheet for Online Survey


If you are aged over 18 years and live in the London area or are willing to travel to London, and are either:

  • currently using cannabis or 
  • never used it / used it less than three times in your lifetime,

Dr Marta Di Forti and her research team would like to invite you to participate in our research project.


It is important that you decide whether you wish to take part in the study only after reading carefully about what it involves, thinking about it and even discussing it with others. Take your time before deciding.


All participant information is anonymised and can only be accessed by the team of researchers involved in the study. No 3rd party will ever be allowed access to the study's data under any circumstance.


We are available to provide further information or answer any questions you might have. Please email: cannabisandme@kcl.ac.uk


What is the purpose of the study?


Cannabis is used daily by some 200 million people worldwide. While many people who use cannabis report benefits – both for recreational and medicinal uses – others experience unpleasant effects, particularly affecting their mental health.


Therefore, at a time when cannabis use is increasing worldwide, this study focuses on understanding the wider impact of cannabis use on the physical and mental health of cannabis users. It also aims to identify environmental and biological factors, which can explain the different effects people experience when using cannabis, and in particular, identify those users more likely to experience mental health and social issues.


The study is fully funded by the MRC, it is based at King’s College London and it involves two parts.


Part 1: The Survey

In the first part of the study, you will be invited to complete, using a computer, smartphone or tablet, an online survey (~30 minutes). The questionnaire aims to explore firstly, the different effects that people experience when they use cannabis and how these might relate to other recreational drug use, live events, including trauma or illnesses, but also positive situations and social context.

Secondly, we are interested in understanding how mood, anxiety and changes in the way we feel or think in general and in particular in social situations might influence the use of cannabis and vice-versa. To better understand the latter we need a comparison group.

Therefore, we invite to complete the online survey both participants who are currently using cannabis, as well as those who have never used it in their lifetime or have only used it a maximum of three times. In addition, participants must meet the following inclusion criteria:

  • Age over 18 years

  • Resident in the London area or willing to travel to London

  • Fluent in English

  • Willing to take part in the face-to-face assessment

  • Willing to donate a blood sample

  • Willing to take part in a virtual reality (VR) experience

  • No previous or current diagnosis of psychotic disorders

  • Not currently receiving treatment for psychotic disorders

All participants who complete the online survey will be entered into a prize draw to win a £100 e-voucher.

Part 2: Face-to-Face Interviews

A sub-group of all the participants from both the current cannabis users and the never/only once or twice groups, who completed the online survey, will be invited to come to the Institute of Psychiatry Psychology and Neuroscience, King’s College, Denmark Hill, London to meet the research team and complete a face-to-face assessment.