UK researchers have launched a study into the effects of cannabis on the human brain, with 6,000 Londoners aged 18 to 45 taking part.
King’s College London’s Cannabis & Me project will focus on people living in the English capital who either currently use the drug, have used it less than three times or have never tried it before.
It will start with a 40-minute online survey that will ask participants about their experience with cannabis and why they took it — for example due to trauma, illness or socially.
The questionnaire will also aim to discover how mood, anxiety and changes in the way participants think and feel influences their cannabis use.
Following the survey, a sub-group will be invited for a face-to-face assessment involving more in-depth questions, a blood test to measure CBD, THC and endocannabinoid levels and a virtual reality social scenario involving cannabis use.
The researchers said it was “paramount” to understand the science behind the drug, with more than 200 million daily users worldwide and numbers rising along with legalisation.
Study lead Dr Marta Di Forti said: “Cannabis is consumed daily by many recreationally, but also for medicinal reasons.
“Our study aims to provide data and tools that can make physicians in the UK and across the world more confident, where appropriate, in prescribing cannabis safely.”
In a separate study, the same information will be collected from people receiving treatment for psychosis, where cannabis use is thought to be the cause.
The aim of this arm is to determine whether biological factors make a person more susceptible to developing psychosis from cannabis use and if a screening test could identify those at risk.