Association Between Baseline Corticothalamic-Mediated Inhibitory Control and Smoking Relapse Vulnerability

Area of Science:

• Neuroscience
• Addiction Research
• Neuroimaging

Background:

• Tobacco use disorder (TUD) is linked to impaired neurocognitive function, particularly within the right inferior frontal gyrus (IFG), a key component of the corticothalamic inhibitory control (IC) network.
• Understanding the neural underpinnings of lapse and relapse is crucial for developing effective smoking cessation interventions.

Purpose of the Study:

• To investigate the relationship between the structural and functional integrity of the IC neural circuitry and the vulnerability to lapse and relapse in adult smokers.
• To identify specific neural markers associated with relapse risk in two independent cohorts.

Main Methods:

• Two independent studies involving adult smokers were conducted.
• Study 1: 81 treatment-seeking smokers underwent functional magnetic resonance imaging (fMRI) during an IC task before a quit attempt, with 10-week follow-up for relapse.
• Study 2: 26 smokers performed an IC task with fMRI, followed by a laboratory-based smoking relapse analog task.

Main Results:

• In Study 1, smoking relapse was associated with reduced gray-matter volume, increased right IFG and thalamus IC task-related blood oxygenation level-dependent (BOLD) response, and weaker corticothalamic task-based functional connectivity (tbFC).
• Study 2 findings mirrored Study 1, showing greater right IFG IC-BOLD response and weaker corticothalamic tbFC were linked to earlier smoking during the relapse analog task.
• In both studies, corticothalamic tbFC mediated the relationship between IC performance and smoking outcomes.

Conclusions:

• Baseline differences in corticothalamic circuitry function are associated with impaired IC and increased vulnerability to smoking relapse.
• These findings suggest that interventions targeting corticothalamic neurotransmission and enhancing IC could be beneficial for treating TUD.