Researchers have come up with some excellent news for all smokers thinking of kicking the habit. They have discovered that the dopamine imbalances in the brain caused by nicotine consumption are completely reversed within three months of giving up. Aside from indicating that smoking doesn’t cause lingering mental deficits, the study also provides evidence that those who stop smoking face no increased risk of relapsing.
Publishing their study in the journal Biological Psychiatry, the authors note that this finding came as something of a surprise, as it had been assumed that long-term exposure to addictive drugs like nicotine produces lasting changes in users’ brains, leaving them more susceptible to returning to these drugs even after giving up. Smoking, for instance, has been shown to interfere with dopamine production in a brain region called the basal ganglia, which is heavily involved in controlling the formation of habits.
Though scientists have struggled to understand why some people appear to be more vulnerable to addiction than others, one popular theory is that these temporary effects eventually cause the brain to lose its ability to regulate dopamine levels. Since dopamine is a neurotransmitter that plays a central role in generating feelings of pleasure and reward, imbalances can cause people to engage a range of harmful behaviors.
The study authors scanned the brains of 30 smokers using a technique called positron emission tomography, comparing their capacity for dopamine production to a group of non-smokers. Scans showed a 15 to 20 percent reduction in this dopamine-producing capacity in the basal ganglia of the smoking group.
However, half of these smokers went on to give up, and scans taken after three months of abstinence showed that their dopamine levels had returned to normal, matching those of people who had never even touched a cigarette.
While this is obviously good news for the individuals involved, it has left the researchers somewhat baffled, as it would appear to disprove one of the leading hypotheses regarding why people are so often reeled back in by the allure of cigarettes even after quitting. The fact that dopamine deficits can’t be used to explain this means that those who go back to smoking will have to come up with another excuse.