Mapping brain functional alterations in betel-quid chewers using resting-state fMRI and network analysis

• Published in: Psychopharmacology Vol. 235; no. 4; pp. 1257 - 1271
• Main Authors: Weng, Jun-Cheng, Chou, Yu-Syuan, Huang, Guo-Joe, Tyan, Yeu-Sheng, Ho, Ming-Chou
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-04-2018; Springer; Springer Nature B.V
• Subjects: Adult; Alcohols; Alternations; Areca; Basal forebrain; Betel (Piper betle); Biomedical and Life Sciences; Biomedicine; Brain - drug effects; Brain - physiopathology; Brain mapping; Brain Mapping - methods; Brain research; Carcinogens; Case-Control Studies; Drug abuse; Drug addiction; Female; Forebrain; Functional magnetic resonance imaging; Homogeneity; Humans; Inhibition, Psychological; Magnetic Resonance Imaging - methods; Male; Mastication; Middle Aged; Neural networks; Neurosciences; Nicotiana - adverse effects; Original Investigation; Pharmacological research; Pharmacology/Toxicology; Psychiatry; Psychological aspects; Psychopharmacology; Regional analysis; Reinforcement; Reward; Rewards (Psychology); Substance abuse; Substance use; Substance-Related Disorders - physiopathology; Theoretical analysis; Tobacco; Variation; Young Adult; Resting-state functional MRI (rs-fMRI); Graph theoretical analysis (GTA); Network-based statistical (NBS) analysis; Functional connectome; Betel quid
• ISSN: 0033-3158; 1432-2072
• DOI: 10.1007/s00213-018-4841-8

Rationale
The World Health Organization regards betel quid (BQ) as a human carcinogen, and DSM-IV and ICD-10 dependence symptoms may develop with its heavy use. BQ’s possible effects of an enhanced reward system and disrupted inhibitory control may increase the likelihood of habitual substance use.
Objectives
The current study aimed to employ resting-state fMRI to examine the hypothesized enhanced reward system (e.g., the basal forebrain system) and disrupted inhibitory control (e.g., the prefrontal system) in BQ chewers.
Methods
The current study recruited three groups of 48 male participants: 16 BQ chewers, 15 tobacco- and alcohol-user controls, and 17 healthy controls. We used functional connectivity (FC), mean fractional amplitude of low-frequency fluctuations (mfALFF), and mean regional homogeneity (mReHo) to evaluate functional alternations in BQ chewers. Graph theoretical analysis (GTA) and network-based statistical (NBS) analysis were also performed to identify the functional network differences among the three groups.
Results
Our hypothesis was partially supported: the enhanced reward system for the BQ chewers (e.g., habitual drug-seeking behavior) was supported; however, their inhibitory control was relatively preserved. In addition, we reported that the BQ chewers may have enhanced visuospatial processing and decreased local segregation.
Conclusions
The current results (showing an enhanced reward system in the chewers) provided the clinicians with important insight for the future development of an effective abstinence treatment.