Some people may be more genetically prone to cannabis addiction, a study led by UCL has found.
Researchers found that three genetic markers – which have previously been implicated in cannabis addiction but have not been considered in the same study before – were linked with cannabis addiction-related responses.
“We were interested in asking whether these genetic markers could predict addiction-related responses after inhaling doses of cannabis, such as how much our attention is drawn to cannabis-related pictures,” said lead researcher Dr Chandni Hindocha (UCL Clinical Psychopharmacology Unit).
For the study, 48 cannabis users took cannabis using a vaporiser, and conducted tests related to addiction predisposition: a test for drug cue salience (how attention-grabbing cannabis-related images were versus neutral images, such as side-by-side images of a woman smoking cannabis and a woman holding a pen near her mouth); a satiety measure (testing whether they still want more cannabis after they’ve already had some) and a craving measure. The 48 cannabis users were also tested for the three genetic markers.
The researchers found differences in drug cue salience and state satiety for all three genetic variants. One genetic marker in particular, associated with the Cannabinoid receptor 1 gene, was associated with people continuing to want more cannabis after having used it, and continuing to be more drawn to cannabis-related imagery while under the influence. The researchers say this suggests that people with that genetic marker could be more prone to cannabis addiction, especially as THC, the psychoactive component in cannabis, binds to this receptor.
The researchers say it is easy to test for these genetic variants, but that more research is needed to optimise such a test.
Dr Hindocha said: “We hope that our findings could lead to the development of a test that could inform clinicians who are considering prescribing a cannabis-derived medication, as we learn more about which genes affect how people react to cannabis.”
The study’s senior author Professor Val Curran (UCL Clinical Psychopharmacology Unit) said:
“There’s still more work to be done to clarify how these genetic variants impact drug effects, and to identify what other factors should be considered to gauge how vulnerable someone is to cannabis addiction. With time, we hope that our results could pave the way towards more personalised approaches to medicinal cannabis prescription.”
