Altered Functional Connectivity in the Reward Circuit in Betel Quid-Dependent Chewers

Area of Science:

• Neuroimaging
• Addiction Neuroscience
• Public Health

Background:

• Betel quid (BQ) is a Group 1 carcinogen, posing a significant public health risk.
• Betel quid dependence (BQD) is associated with changes in brain reward regions.
• Neural correlates of BQD's reward circuit and its link to clinical features are not well understood.

Purpose of the Study:

• To investigate resting-state functional connectivity (FC) within the reward circuit in individuals with BQD.
• To explore the neural correlates of aberrant FC with clinical features of BQD.
• To identify potential circuit-level biomarkers for BQD.

Main Methods:

• Recruited 53 male BQD chewers and 53 male healthy controls (HCs).
• Utilized resting-state functional magnetic resonance imaging (rs-fMRI) to analyze FC in 11 reward circuit regions (e.g., ventral striatum, VMPFC, ACC, PCC, thalamus).
• Correlated aberrant FC with BQD scales and dosage of BQ use.

Main Results:

• Individuals with BQD showed altered FC in reward circuit regions, including the thalamus and PCC, compared to HCs.
• Decreased FC between the right thalamus and PCC negatively correlated with BQD severity and BQ dosage.
• This study provides the first empirical evidence of aberrant resting-state FC in the reward circuit in BQD.

Conclusions:

• Aberrant resting-state FC in the reward circuit is a key feature of BQD.
• The thalamus-PCC connectivity may serve as a potential circuit-level biomarker for BQD.
• Understanding reward circuit dysfunction is crucial for the pathophysiology of BQD.