It’s well established that drinking alcohol can make it harder to control your behavior. But what if you just sniff it? Apparently that has an effect, too. Researchers say people who sniffed alcohol scored lower on an impulse-control test than people who inhaled a citrus smell.

The study, published in the journal Psychopharmacology, was designed to find out how the sight and smell of alcohol might affect drinkers’ brains even before they start drinking—or trying not to drink. Psychologists recruited 40 self-described social drinkers (21 female and 19 male) between the ages of 19 and 48. Each person then got a little mask soaked in solution. Half of the masks were soaked in a vodka solution, while the other half were doused in a citrus oil solution.

While wearing their masks, the participants played a computer game called a go/no-go association test (GNAT), which measures implicit social cognition, or our unconscious responses (which may be socially learned). Once again, there were two groups, but each group contained half alcohol-sniffers and half citrus-sniffers. Participants in the neutral group were quickly shown letters of the alphabet and told to push the button when they saw the letter K. People in the experimental group had to look for a beer bottle amid 25 different water bottle photos.

The object of the game was to press the button only when the letter K or the beer bottle appeared; in other words, it was a test to see how well the participants could control their impulse to hit the button (the "go/no-go" factor). 

They found that people looking for the beer bottle were better at restraining themselves than those looking for the letter K. But the participants with alcohol-soaked masks had significantly lower impulse control than those breathing a citrusy scent. 

If just the smell of booze is enough to lower our inhibitions, the researchers say, it’s not a huge surprise that people find it so hard to quit drinking. This was a small study, but it represents an important direction in alcohol and substance abuse research, the researchers say.

"This research is a first attempt to explore other triggers, such as smell, that may interfere with people's ability to refrain from a particular behavior,” co-author Rebecca Monk said in a press statement. "For example, during the experiment, it seemed that just the smell of alcohol was making it harder for participants to control their behavior to stop pressing a button.”

Her co-author Derek Heim added that studies like this will lead to better evidence-based programs to help people break problematic habits. "Our hope is that by increasing our understanding of how context shapes substance-use behaviors, we will be able to make interventions more sensitive to the different situations in which people consume substances."