Could Virtual Reality Help Fight Cannabis Use Disorder?Joe WilsonNovember 30, 2016
A team led by Melissa Norberg, a psychology professor at Sydney’s Macquarie University, this month published a systematic review of cannabis cue-reactivity studies in the journal Addiction. Cues are the objects or actions that can trigger strong cravings in dependent drug users. Cue-reactivity is the combination of our responses to cues, related attentional biases, and craving.
“Our systematic review showed that individuals who regularly smoke cannabis pay a lot of attention to cues associated with use,” Norberg said. And virtual reality could be an important tool in helping reduce the impact of those triggers. “There may be potential for the use of VR for people who want to stop using cannabis.”
Replicating cues in virtual reality environments could be used in so-called non-use training. The idea is that subjects are shown the cues they associate with cannabis but then aren’t given an opportunity to consume. In theory, the training weakens the learned associations between a trigger and the desire to consume. Virtual reality could allow for realistic exposure to cues in controlled research and clinical environments.
“Therapists are not able to attend parties with their clients,” Norberg pointed out. “Thus, they are unable to directly help someone resist smoking weed at a party, but they could indirectly help someone with VR. Party paradigms can be created, and individuals can practice seeing cues in the VR environment and then not smoke.”
One of the studies that was canvassed but ultimately excluded from Norberg’s review was a 2009 paper from a team of scientists led by Patrick S. Bordnick of the University of Houston. In that study, Bordnick played cannabis consumers five minutes of classical jazz (for reasons not explained in the paper), and then used virtual reality to expose them to cues—such as cannabis accessories or someone rolling a joint—associated with consumption.
The study found that exposure to such cues had a significant effect on self-reported cravings for cannabis compared to subjects shown “neutral” imagery.
Another study, published in Frontiers in Human Neuroscience in 2014, looked at how virtual reality might be used to meet “the unmet clinical need” of suppressing cravings among people struggling with substance disorders. The study found that across a range of substances, exposure to cues in virtual reality environments was successful in inducing cravings. As technology improves and virtual reality environments become more realistic, subjects will be able to interact with those in more complex and sophisticated ways, potentially opening the door to new treatment options.
In Australia, however, Norberg cautioned that virtual reality “as a standalone” may have some limitations. Among them is the difficulty of incorporating surprise, an important learning tool in exposure therapy. In other words, people expecting to be exposed to cues may not benefit from that exposure in the same way. It’s a phenomenon that hasn’t yet been tested with respect to cannabis, Norberg said, although “we definitely need research in this area to inform how and under what circumstances VR might be helpful to individuals who no longer wish to use cannabis.”