Smokers who attempt to quit but end up relapsing within seven days exhibit specific disruptions in the brain’s working memory system during their time of smoking abstinence, according to a new study by Penn Medicine.
This distinct neural activity — mainly a decrease in the part of the brain that supports self-control and an increase in the area that promotes an “introspective” state — could help distinguish successful quitters from those who fail at an early stage; it may also reveal a potential therapeutic target for new treatments.
“This is the first time abstinence-induced changes in the working memory have been shown to accurately predict relapse in smokers,” said senior author Caryn Lerman, Ph.D. a professor of Psychiatry and director of Penn’s Center for Interdisciplinary Research on Nicotine Addiction.
For the study, published in the journal Neuropsychopharmacology, researchers used functional magnetic resonance imaging (fMRI) to observe the effects of brief abstinence from smoking on working memory and its associated neural activation. The 80 participants, aged 18 to 65, reported smoking more than 10 cigarettes a day for more than six months and were currently seeking treatment.
“The neural response to quitting even after one day can give us valuable information that could inform new and existing personalized intervention strategies for smokers, which is greatly needed.” said James Loughead, Ph.D., associate professor of Psychiatry.
Past research strongly suggests that if a person can go without smoking for seven days, he or she will likely continue that way for six months or longer, and is therefore highly predictive of long-term success.
The researchers conducted two brain scans: the first immediately after a person smoked and the other 24 hours after abstinence began. Following smoking cessation counseling, participants set a future target quit date. Seven days after the target quit date, participants had a check-up, during which smoking behavior was accessed, including a urine test.
Sixty one smokers relapsed and 19 quit successfully for this period, the researchers reported.
Those who relapsed had decreased activity in the left dorsolateral prefrontal cortex, which controls executive functions, like working memory, compared to those who quit. Working memory is necessary for staying focused, blocking distractions, and completing tasks. They also had reduced suppression of activation in the posterior cingulate cortex, a central part of the default mode network of the brain, which is more active when people are in an “introspective” state.
Although wide implementation of a neuroimaging test is not clinically or economically feasible at this time, these findings on working memory may lead to improved measuring tools, specifically for early smoking relapse.
Source: Penn Medicine