Q: Can you explain about paranoid responses?
A: “We go through the questionnaires looking at people’s paranoid response to everyday life, not in a clinical disorder term, just in terms of the differences in how we respond to certain circumstances. For example: ‘How do you feel if someone’s staring at you on the Tube?’ Some people are afraid, some feel uncomfortable, some people don’t notice, and others think a person is staring at them as they look good or another such positive feeling. So, we give people a paranoia score and will invite some at the top and some at the bottom of that score for a face-to-face assessment. We want to select those people who are using cannabis daily and they are getting either no paranoia or high paranoia.”
Q: What happens at the face-to-face assessments?
A: “We do two things which are very novel. We ask them to take part in a virtual reality experience. They are in a lovely shop and within this experience they come across challenges, which may or may not induce a benign paranoia response. We will ask them to donate a sample of blood before they go into the VR set. We will test for tetrahydrocannabinol (THC) and cannabidiol (CBD). We will also look at the metabolites of the two. People don’t take into account how differently individuals metabolize cannabis, which could be one of the reasons why some people can tolerate it and others can’t.”
Q: There’s also a genetic aspect of the study?
A: “From the same sample, we will extract DNA to look at the genetics across the genome and compare genetic variations between high and low paranoia in the context of cannabis use. Also, we will look at the epigenetics, as we have learned from neuroscience, and also cancer, that sometimes a substance we ingest has an effect on our health. It’s perhaps an interaction with the way our DNA is written but also with the changes to the way our DNA is read and translated into biology if exposed to that substance. We know that smoking tobacco does have an impact at an epigenetic level on the DNA. We do know that in people who stop smoking, these impacts on the epigenetics are partially reversed. This work hasn’t been done properly for cannabis.
“There have been four published studies that have looked at the effect of cannabis use on epigenetics but they have been quite inconclusive, and they haven’t looked at large numbers of current users taking into account how much they are using. Moreover, we do know that when THC and CBD get into our bodies, they interact with something that is already embedded in our biology which is the endocannabinoid system. Therefore, in the blood samples we also aim to measures the levels of the endocannabinoids we naturally produce.
“All of this data will then be analyzed to see if we can get close to understanding what makes some cannabis users susceptible to paranoia while others who are using cannabis get some benefits, even in the domain of mental health.”