Nicotine is addictive, clearly. But what does that really mean? For one, when you don’t have the drug in your bloodstream, you crave it physically — by the anxiety and irritability of withdrawal popping up only a few hours after the last hit. And then there's the mental dependence. This is where things get tricky. “Addiction is not just about the drug itself,” says Xiaosi Gu, an assistant professor at the Center for Brain Health at the University of Texas at Dallas. “Your own belief has a very big role in it.”

If this were truly the case, you’d think that what a smoker believes about the nicotine content of a cigarette actually could change their cravings. This, according to a recent study published in the journal Frontiers in Psychiatry, turns out to be exactly the case.

Researchers at Baylor College of Medicine in Houston gave 24 smokers a cigarette either with or without nicotine, asked them about their cravings for nicotine, and put them in an fMRI to scan brain activity after smoking. The twist is, half the time the researchers didn’t tell study participants the truth about which kind of cigarette they were getting. Each study participant came in four times, smoking every combination of a cigarette with or without nicotine, with a true or false idea about its nicotine content.

The smokers in the study only felt their cravings satisfied when they smoked nicotine cigarettes and believed they got nicotine cigarettes, the researchers found. When the smokers didn’t think they got a cigarette with nicotine — even if they actually did — they kept craving one. The insula, a brain area involved in emotion and craving, didn’t react as strongly to a cigarette with nicotine if the study participant was told they were smoking a nicotine-free cigarette. “The mind is still really powerful even in a situation like this, with a very strong drug,” Gu says.

Still, believing a nicotine-free cigarette did contain nicotine wasn’t enough to trick smokers’ brains into not craving the drug anymore. The placebo effect, which would predict that smokers would experience some satisfaction in this scenario, didn’t show up. In the case of nicotine, Gu says, “I think the drug is so potent that it has to be there for the brain to have a response in the first place.”

While the research doesn’t yet suggest any new techniques for smokers trying to kick the habit, it does shed some light on currently available therapies. Trying to substitute a nicotine patch or gum for smoking, though it works for some, isn’t going to fool you into thinking that you’ve smoked and should feel satisfied, just because you’re getting a little nicotine. On the other hand, the research shows that belief, the target of cognitive behavioral therapy to quit smoking, has a biological effect in the brain when it comes to processing nicotine. “We know that when people talk about belief, it's not something vague or only psychological,” Gu says. “You need to believe that you need the nicotine in order for nicotine to have an effect on your brain.”

For access to exclusive gear videos, celebrity interviews, and more, subscribe on YouTube!