Dysfunction of the Prefrontal Cortex in Betel-Quid–Dependent Chewers

Abstract

Betel quid is the fourth most popular psychoactive agent worldwide. Imaging studies have found altered brain structure in prefrontal cortex (PFC) in betel-quid dependent (BQD) chewers. However, the brain function in PFC associated with BQ use still remains unclear. The present study aimed to examine brain functional activity in PFC in individuals with BQD. This study recruited 48 participants with BQD and 22 normal controls (NCs). Both BQ-specific cue reactivity and Go/NoGo tasks were administered with functional magnetic resonance imaging (fMRI). Behavioral results showed a deficit in the choice reaction time task in BQD group. The fMRI results of the cue reactivity task suggested that, individuals with BQD exhibited responses in right ventromedial PFC, left posterior cingulate cortex (PCC), left lateral parietal lobe (LPL), left middle temporal gyrus and left visual cortex, when seeing BQ images compared with control images. In the Go/NoGo task, relative to NCs group, individuals with BQD showed higher activity in right dorsolateral PFC, right PCC and bilateral LPL between NoGo and Go trials. Across these two tasks, we consistently found disrupted function in PFC in individuals with BQD, which might lead to impaired craving and response inhibition in BQ addiction. Results of current study might shed light on the neural mechanisms involved in BQ use, which could be used as potential guidelines for diagnosis and treatment of BQ dependence.

On multifaceted inhibitory control in betel-quid-dependent chewers

“…It is not clear how to account for the inconsistency between intact behavior inhibition in the BQD vs. the possible dysfunction of dlPFC in the same group. At least, according to behavioral evidence (Ho et al, 2015;Kong et al, 2020) along with the current result, we suggest an intact prepotent response inhibition in BQ chewers.…”

“…Concurrent use of cigarettes and alcohol was taken into account by adopting controls for tobacco and alcohol users (Ho, 2014(Ho, , 2021. Previous BQ studies on inhibitory control (e.g., Kong et al, 2020;Zhu et al, 2018) excluded participants who met the DSM-IV criteria for dependence on alcohol and nicotine. However, alcohol and cigarette use for BQ chewers and healthy controls who did not meet the DSM-IV criteria is not reported.…”

“…Impaired inhibitory control is closely related to increased impulsivity (de Wit, 2009), increasing the probability of drug-seeking behaviors. However, to our knowledge, there are very few behavioral studies on inhibitory control of BQ chewers (Ho et al, 2015;Kong et al, 2020;Zhu et al, 2018). Ho et al (2015) used the stop-signal task to measure inhibitory control after one night of normal or deprived sleep.…”

“…The behavioral data showed the comparable correct rates for the BQD and the non-chewers. Alternatively, Kong et al (2020) reported increased activation in brain areas, including the right dlPFC in the BQD. A possible dysfunction of the prefrontal area in BQ addiction is suggested.…”

Altered Spontaneous Brain Activity in Betel Quid Dependence Chewers: A Resting-State Functional MRI Study With Percent Amplitude of Fluctuation

“…The cortical thickness of the dlPFC was found to have a significant role in mediating executive function deficits among BQD chewers in a recent study ( 29 ). Moreover, dysfunction of functional activity in the dlPFC may relate to diminished cue-induced hankering and responding suppression in BQD ( 30 ). The dlPFC is also involved in decision-making ( 31 , 32 ).…”