By Wendy Anson, Ph.D.
“I had a big ‘AHA’ moment in the ’90s when we wanted to see if giving people genetic feedback about their risk for lung cancer would increase their ability to quit smoking,” said Dr. Caryn Lerman, John H. Glick Professor of Psychiatry at the University of Pennsylvania, who was selected as the 2016 distinguished scholar to deliver OBSSR’s Matilda White Riley Lecture for Excellence in Behavioral and Social Sciences.
Dr. Lerman was shocked by what her team learned because, during that era, there was a lot of emphasis on simply educating people about the dangers of smoking. “Smokers who received the feedback that they were at higher risk for lung cancer changed their attitudes and beliefs and had a great number of quit attempts but were no more able to quit smoking than those who did not receive that feedback.”
Exciting development: Identification of neural biomarker that predicts relapse in nicotine-dependent smokers
When a person quits smoking, explained Dr. Lerman, the most vulnerable period is within the first 72 hours after the quit attempt; in fact, most smokers relapse in this period and many relapse in 24 hours. Her lab has been focused on identifying what precisely changes in the brain when people give up nicotine and if the extent and pattern of those changes can tell us who is going to relapse.
She began a series of studies looking at smokers of various genders, ages, and certain mental health states. “We are discovering that many smokers experience subtle deficits in certain areas of executive cognitive function which is critical to self-control. Working memory-related deficits appear to be important to predict somebody’s relapse risk.”
What changes in the brain when people quit nicotine? Could extent & pattern of changes tell who is going to relapse?
This work seems to bring interesting possibilities to bear on what we generally think of as “cravings” or “will power.” It’s all very well to remember the admonition to “put down that pack of cigarettes and go for a walk,” but self-control is dependent on stronger forces than just keeping “the right thing to do” in mind. Actually, all of these factors interact, Dr. Lerman explained.
“Our lab extended this work early on into neuroimaging with fMRI and found that working memory deficits occur in the first 24 hours after quitting and are associated with distinct patterns of brain activity such as reduced activity in the brain’s frontal cortex.”
She and her group studied changes in networks of brain regions that are relevant to self-control. Cognitive functions, such as attention, working memory, and executive function are all part and parcel of “cognitive self- control.”
When she and her colleagues scanned smokers on a day when they were smoking as usual and then again on the day after they had been abstinent for 24 hours, they saw that, during smoking abstinence, there was a reduction in activity in brain regions critical for working memory and self-control (the frontal part of brain). The results also showed changes in connectivity in the brain between large scale brain networks.
“To stay focused on a goal, people need to actively use their attention,” Dr. Lerman said. Another benefit of taking control of one’s attention is that this directed attention can distract from the cigarette cravings. For example, one could focus on an enjoyable game with friends or family to distract oneself.
Working memory is important too, as it helps people stay focused on goals, remember the goal, and remember the strategies they can deploy. Other aspects of cognitive control are also significant to self-control such as planning and goal setting. Dr. Lerman claims that cognitive function and self-control are interrelated; in the face of a severe craving to smoke, one needs to shift attention from the internal sensation of craving back onto their goal, remembering all reasons that the goal is important. That will increase the likelihood they can attain it.
This research also touches upon behavioral inhibition, response inhibition, the ability to not engage in automatic habitual action.
Reaching for a cigarette or resisting that tendency to act rely on overlapping brain regions. To resist acting depends on a complex set of cognitive functions, similar to what is required to stay on a diet.
Science is just beginning to learn about brain regions and networks. In the next step, Dr. Lerman’s team will focus on how they can use neuromodulation techniques, like trans-cranial direct current electrical stimulation (tDCS) of the brain, in conjunction with medication and cognitive training; “all of this to increase [the] possibility that people can abstain from what has become a harmful habit,” she said.
As far as Dr. White Riley’s emphasis on the “biopsychosocial,” Dr. Lerman says that she and her colleagues are moving even further toward that construct. “My current work is heavier on the ‘biopsycho’ piece of that,” she laughed. “However, in this next study, we are bringing more of the social environment into the research; we are expanding our focus to brain responses to smoking cues in the physical and social environment, as well as ‘social evaluative stressors,’ where researchers will be telling them that they are ‘not performing a task well’ or that they are ‘performing below average.’”
Dr. Lerman explored how these discoveries have rich implications in this new era of personalized medicine. “Tying together brain responses to a variety of psychological, cognitive, and social factors, we might be better able to predict who is going to relapse. This will also give us more insight into individual differences in tobacco dependence. Understanding what may be unforeseen challenges for some smokers as opposed to others will help us to develop more targeted interventions to address smokers’ individual needs.”
The distinguished scholar is quick to heap praises over her inter-disciplinary colleagues and collaborators, past and present: “All of this work was done through a series of collaborations with colleagues at the University of Pennsylvania, across [the] country and across [the] world, and been a true team science effort all along the way.”
“Trans-disciplinary science—one of the major structural factors that made it possible to get as far as we have—was a novel NIH initiative. We were fortunate to receive one of the first trans-disciplinary Tobacco Use Research Centers, the TTURC grants from NCI [the National Cancer Institute] and NIDA [the National Institute on Drug Abuse].”
Dr. Lerman went on to describe the “incredible initiative” that supported them through the decade, beginning in 1999; which “provided the very first scientific foundation for trans-disciplinary team science for tobacco dependence.”
Dr. Lerman’s eyes lit up as she described the kind of experience many practicing scientists and researchers remember most fondly from their work. “Many people at NIH participated as we all learned together what trans-disciplinary science is and why it’s important; that was a transformational initiative, without which the field and we would not be where we all are today.”
Dr. Matilda White Riley would be proud.
On June 20, Dr. Lerman will deliver the 9th Matilda White Riley Lecture for Excellence in Behavioral and Social Sciences titled “Bridging Behavioral and Cognitive Neuroscience Research to Advance the Treatment of Tobacco Dependence.” The event will take place at the United States Institute of Peace in Washington, DC. It is free and open to the public, but registration is required.
Photo Credit: Shutterstock/Vitstudio
