Pot smokers aren’t strangers to the waves of anxiety that follow a puff or six. But plenty of anxious people are keenly aware of how much a joint can help. The two-way interaction between marijuana and nervousness has long been hazy, but a new paper in the journal Addictive Behaviors Reports provides evidence that there’s a fundamental link between the way pot smokers and people with anxiety disorders deal with the world. This may go a ways toward explaining why what chills us out also makes us worry.

Over the years, researchers have determined that people with anxiety tend to focus their eyes on threatening images — say, a bloodied face — for shorter periods of time than those who don’t. It’s a phenomenon called “attentional bias,” which suggests a tendency toward avoidance that the British researchers behind the new study wanted to assess in marijuana users.

To assess their tendency toward avoidance, participants were asked to gaze at pairs of threatening and non-threatening images.

Taking eight daily pot smokers and 15 non-smokers as a control group, the researchers administered a gaze-tracking test in which each person was shown a pair of photos, one of which contained a small dot. The objective was simple: Find the dot. The images, as you might expect, weren’t entirely benign; in each pair, one was emotionally neutral — say, a photo of a book — while the other was “anxiety-related” — like a picture of a rattlesnake.

The researchers tracked participants’ eye movements as they searched for the dots. They found, as expected, that the pot smoking group spent significantly less time looking at the anxiety-related photos than their weed-free counterparts. The behavior was very much in line with the behavior of people suffering from anxiety disorders. This led the researchers to conclude that pot smokers and people with anxiety disorders react to threatening stimuli in the same way: They avoid them.

What does this mean for smokers? Extrapolation is an uncertain business, but it seems to suggest that pot eases the anxiety of coping with negative external stimuli over the short term, but makes doing so harder over the long term. The question of whether or not people become pot smokers because they have anxiety issues or vice versa is largely unresolved — this seems to indicate that pot smoking itself has a mental toll.

It’s a small study, and it doesn’t clear up the chicken-egg relationship between anxiety and weed. But it does suggest that the relationship is a real one — one that’s worth considering the next time an anxious person reaches for a joint or a psychiatrist reaches for her prescription pad.

Photos via Wilcockson, Sanal, et al., David Ramos/Getty