Functional Correlates of Resting-State Connectivity in the Default Mode Network of Heroin Users on Methadone Treatment and Medication-Free Therapeutic Community Program

Li-Wei Kuo,Shih-Yen Lin,Hengtai Jan,Ming-Fang Liu,Pei-Sheng Lin,Hsin-Chien Lee,Sheng-Chang Wang

doi:10.3389/fpsyt.2019.00381

Abstract

The treatment of heroin addiction is a complex process involving changes in addictive behavior and brain functioning. The goal of this study was to explore the brain default mode network (DMN) functional connectivity using resting-state functional magnetic resonance imaging (rs-fMRI) and decision-making performance based on the Cambridge gambling task in heroin-dependent individuals undergoing methadone treatment (MT, n = 11) and medication-free faith-based therapeutic community program (TC, n = 11). The DMN involved the medial prefrontal cortex (mPFC), left inferior parietal lobe (IPLL), right inferior parietal lobe (IPLR), and posterior cingulate cortex (PCC) subregions for all participants in both the MT and TC groups. Compared with MT, TC had an increased functional connectivity in IPLL–IPLR and IPLR–PCC and decreased functional connectivity in mPFC–IPLL and IPLL–PCC. Both groups exhibited no significant difference in the regional rs-fMRI metric [i.e., amplitude of low-frequency fluctuation (ALFF)]. In the analysis of the neural correlates for decision-making performance, risk adjustment was positively associated with ALFF in IPLL for all participants considering the group effects. The involvement of IPL in decision-making performance and treatment response among heroin-dependent patients warrants further investigation.

Highlights

Heroin addiction is a chronic brain disorder involving interacting neural systems that lead to complex addictive behaviors [1]
At the resting-state functional magnetic resonance imaging (rs-fMRI) session, 54.5% (6/11) and 9.1% (1/11) of the participants in the methadone treatment (MT) group were tested positive for morphine and amphetamine, respectively
The present study investigated the rs-fMRI functional connectivity of default mode network (DMN) and its correlation with decision-making performance in heroin users on MT and medication-free therapeutic community (TC) program

Summary

Introduction

Heroin addiction is a chronic brain disorder involving interacting neural systems that lead to complex addictive behaviors [1]. The Iowa gambling task (IGT), a paradigm requiring participants to choose between “risky” options with larger short-term gains offset by greater long-term losses and “safe” ones with smaller short-term gains and losses from an ambiguous and learning context, has been extensively used to measure decision-making performance [3]. It revealed that heroin-dependent individuals had disadvantageous performance with preference of immediate monetary gain regardless of the long-term loss in IGT [4,5,6]. Active heroin users, methadone-treated individuals, and abstinent heroin users were reported to have impaired risk adjustment (RA) with deficit to evaluate the risk probability and calibrate their betting behavior in CGT [11]

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