Neural Correlates and Behavioral Impact of Withdrawal-induced Hyperalgesia Among People Who Smoke With and Without Chronic Pain

Individuals with chronic pain are more likely to smoke cigarettes and have more difficulty quitting smoking than the general population, in part because withdrawal from smoking can lead to temporary increases in pain. This research will examine how smoking withdrawal changes the way the brain processes pain, and whether these withdrawal-related changes interfere with the ability to stop smoking. The results of this research will provide important information that can be used to guide the development of interventions to help people with chronic pain who smoke cigarettes to quit smoking and improve their health.

Eligible participants will complete an initial in-person screening session in which eligibility is confirmed and baseline pain and smoking measures are collected, followed by a sensory testing and training session, in which participants are introduced to the mock MRI scanner and familiarized with the thermal pain stimulation and psychophysiological rating procedures. Participants will then complete two fMRI sessions using a within-subjects, crossover design, with one scan following 24-hrs abstinence from smoking, and the other following smoking as usual. Both fMRI sessions will be identical other than the smoking instructions prior to the scan. During each scan, participants will complete experience and provide ratings to painful heat stimuli. Before and after scanning, participants will complete measures of craving, withdrawal, and current pain level. After completion of the scanning sessions, participants will return to the lab for a baseline visit prior to beginning the abstinence test. During that session, they will have software installed on their smartphone for ecological momentary assessment (EMA), and they will be trained in the procedures for biochemical verification of abstinence. They will then complete 3 days of baseline EMA, during which participants are prompted at 5 random times throughout the day, and once in the evening, to answer questions about their pain, smoking urge, and recent smoking. They will then continue EMA while attempting to abstain from smoking during the 1-week abstinence test. During the abstinence test, each day of abstinence is reinforced with money using a descending schedule. Participants will provide breath samples over video during this week using equipment provided by the lab in order to verify abstinence from smoking. At the conclusion of the study, participants will return to the lab for a final visit to return all equipment.