A recent study conducted in Australia provides evidence that individuals experiencing cannabis use disorder may not automatically pay more attention to cannabis-related images compared to those without the disorder. The findings, which challenge some existing theories of addiction, were recently published in the journal Comprehensive Psychiatry.
Understanding Cannabis Use Disorder and Attentional Bias
Cannabis use disorder is a mental health condition characterized by a problematic pattern of cannabis use that leads to significant impairment or distress. It tends to occur when a person continues using cannabis despite experiencing negative consequences in their daily life.
Individuals with this disorder may have difficulty controlling how often or how much cannabis they use. They may spend a large amount of time obtaining, using, or recovering from the effects of the substance. Another common feature is craving, which refers to a strong desire or urge to use cannabis. People with cannabis use disorder also tend to develop tolerance, meaning they need larger amounts of the substance to achieve the same effects. When attempting to stop, some individuals experience withdrawal symptoms—such as irritability, sleep problems, or reduced appetite.
To better understand why some individuals struggle with these cravings, researchers look at a psychological concept known as “attentional bias.”
Marianna Quinones Valera, a PhD Candidate and RTP Scholarship Recipient at the Australian Catholic University’s Healthy Brain and Mind Research Centre, was the lead author of the study. She explains the concept in accessible terms: “Attentional bias is when people’s attention is automatically focused on something of value or meaning to them. For example, someone who likes coffee might tend to notice coffee shops everywhere without consciously looking out for them.”
“In the same way, a person who consumes cannabis on a regular basis might quickly notice things in their surroundings that remind them of cannabis, like vapes and bongs displayed on a tobacconist’s window,” she adds. “This automatic pull of one’s attention can trigger the urge to use, even when someone is trying to stop.”
The Purpose of the Study
Quinones Valera and her team, consisting of over 20 researchers over the course of four years, wanted to explore how this attentional pull differs between everyday individuals. Specifically, they looked at individuals with moderate-to-severe cannabis use disorder who were not currently seeking treatment, comparing them to a control group of participants who did not use cannabis.
“I became interested in this topic because I want to help people who struggle with addiction understand what can increase their craving, and make it harder to cut down or quit, so that we can target these issues with tailored interventions,” Quinones Valera explains.
The research team also sought to determine whether the strength of this attentional bias depends on factors like how much cannabis a person uses, their level of cravings, or the severity of their cannabis-related problems, while also accounting for other habits like alcohol consumption.
“Research in this area can help explain why some people experience addiction to cannabis and why some people find it harder to quit than others,” says Quinones Valera. “It can also guide treatments that help people shift their focus away from these triggers, and inform policies around how cannabis products are presented to better protect those who may be more vulnerable to cannabis cues.”
How the Research Was Conducted
The study recruited 108 participants from the Melbourne metropolitan area. Participants were between 18 and 55 years of age. Those in the cannabis use disorder group reported daily or almost daily cannabis use for at least the past 12 months and met the clinical diagnostic criteria for moderate-to-severe cannabis use disorder.
To ensure a comprehensive understanding of the participants, the researchers conducted clinical interviews and administered assessments measuring anxiety, depressive symptoms, and motivation to change cannabis habits.
To measure attentional bias, the researchers utilized a computerized visual task. Participants were briefly shown pairs of images side-by-side on a screen: one cannabis-related image (such as photos of the plant, people using it, or paraphernalia like bongs) and one neutral image (everyday people and objects carefully matched in color, brightness, and complexity so they wouldn’t stand out for the wrong reasons).
After the images flashed on the screen, one was replaced by a small arrow. The participant had to quickly press a button indicating which way the arrow was pointing. The underlying logic of the test is simple: if a participant’s attention is already “biased” or drawn toward the cannabis image, they will react faster when the arrow appears in that exact spot, because their eyes are already looking there. Each participant completed 164 of these rapid-fire trials.
Surprising Results: A Break from Expectations
The results of the visual task did not support the initial expectation that participants with cannabis use disorder would naturally have a stronger attentional bias toward the cannabis pictures compared to the control group.
“We expected that people with cannabis addiction—especially those with more severe problems—would show a stronger attentional bias to cannabis-related images than people who don’t use cannabis,” Quinones Valera notes. “However, this is not what we found. Even though participants in our study were experiencing more serious difficulties with their cannabis use, only a small group showed a slight tendency to focus on cannabis cues.”
This raises the question: why wouldn’t these images capture their attention? The researchers suggest habituation may play a role.
“One possible explanation is that people who have used cannabis for a long time may become used to it, so these cues no longer stand out or grab their attention as much,” Quinones Valera suggests. “However, people who have used cannabis for a long time and are undergoing treatment have also shown attentional bias to cannabis cues in other studies. Therefore, more research is needed to understand what other mechanisms could be at play.”
Nuance in the Findings
While a widespread bias wasn’t found across the board, the data did suggest a very slight trend among the most severe cases. Within the group of participants suffering from cannabis use disorder, those with the most severe symptoms tended to have very slightly faster reaction times when the arrow appeared over cannabis images.
However, the researchers caution that this difference was incredibly small, making it unclear whether it represents a true, systemic difference or merely random variation in the participants’ response times.
“Our findings suggest that not everyone who uses cannabis is automatically drawn to cannabis-related images. While some people do notice these cues more easily, this doesn’t happen in every case,” Quinones Valera explains. “It may depend on factors like how serious their cannabis use problems are and how this kind of attention is measured. In our study, only some of the people who experience more severe problems seemed to show an automatic tendency to focus on photos depicting cannabis. However, the difference in this tendency was very small, so we need to study a larger group of people to know whether it truly matters.”
Important Limitations and Looking Ahead
As with all scientific studies, it is vital to view the results within the context of how the research was conducted. Reactions to briefly shown pictures on a computer screen may not perfectly capture how a person reacts to real cannabis in the real world.
“Readers should keep in mind that this study was conducted under experimental conditions where people might be more inclined to show socially desirable answers,” warns Quinones Valera. A “socially desirable answer” occurs when a person consciously or unconsciously alters their behavior to appear more acceptable to the researchers. “For example, our research participants could have given responses that they thought were more acceptable, such as attempting to divert their attention from cannabis images. Future research should focus on testing people in conditions as similar as possible to those in which they normally use cannabis.”
Additionally, the study specifically selected participants who did not suffer from other major psychiatric illnesses. While this helped isolate the effects of cannabis use, it may have resulted in a sample that does not fully represent the broader population of individuals with cannabis use disorder, who frequently experience co-occurring mental health conditions.
“It is also important to note that our findings may only apply to people similar to those in our study, for example, those who experience moderate to severe cannabis use problems, with no other significant mental health concerns and who are not in treatment but have tried to cut down or stop,” she adds. “Clearly, more research is needed to better understand the how and the who behind attentional bias.”
Real-World Implications for Treatment and Policy
Despite the unexpected outcome, the study contributes valuable insight into the scientific understanding of cannabis use disorder and highlights the need to identify exactly who is most vulnerable to visual triggers.
“One of the main goals in this area is to understand who the cannabis consumers are who experience problems with cannabis, have their attention captured by cannabis-related cues and struggle to reduce or stop their consumption,” says Quinones Valera. “Understanding who is more sensitive to experiencing problems with cannabis cues could help us identify who might benefit from treatments that help shift attention away from these triggers. Such treatments have proven helpful in relation to reducing attentional bias to other substances, such as alcohol.”
This research takes on added urgency as the cultural and legal landscape surrounding the drug shifts globally.
“As medicinal and recreational cannabis becomes legal in more parts of the world, its products will become more visible. This means that members of the public will likely be more exposed to cannabis ads, which may make it harder for some people—especially those who are more sensitive to cannabis-related cues—to manage their use or avoid relapse when trying to cut down or stop,” she explains. “Understanding how these cues affect attention can help guide both treatment approaches and policies around advertising, so that people who may be more vulnerable to them are better supported.”
Reflecting on the comprehensive four-year project, Quinones Valera expressed gratitude and shared a final takeaway: “Firstly, we would like to thank our participants for their time and willingness to take part in this study. Their contribution made this research possible. We would also like to thank the over 20 people on the research team for conducting this work. Although our findings were not what we expected, they highlight an important lesson: human behaviour is complex, and results are not always straightforward. Even when we expect to see clear patterns, the reality can be more nuanced.”
The paper, “Attentional bias in people with moderate-to-severe cannabis use disorder,” was authored by Marianna Quinones-Valera, Gary Chan, Madeleine I. Fraser, Andrew Jones, Tom P. Freeman, Chandni Hindocha, Hannah Thomson, Eugene McTavish, Hannah Sehl, Adam Clemente, Janna Cousijn, Izelle Labuschagne, Peter Rendell, Gill Terrett, Lisa-Marie Greenwood, Govinda Poudel, Chao Suo, Victoria Manning, and Valentina Lorenzetti.
