Task-related functional connectivity of the amygdala and impulsivity in methamphetamine use disorder
Poster No:
530
Submission Type:
Abstract Submission
Authors:
Dara Ghahremani1, Jean Baptiste Pochon1, Megan McClintick1, Andy Dean1, Edythe London1
Institutions:
1UCLA, Los Angeles, CA
First Author:
Co-Author(s):
Introduction:
Individuals with Methamphetamine Use Disorder (MUD) exhibit impulsive behavior and negative affect, yet it is not clear if and how these two phenotypes may interact at the neural level. The amygdala has a central role in negative affect and in appetitive processes associated with addiction (e.g., drug cue-induced craving). It is also functionally connected to central components of networks underlying self-control. We investigated the relationship between functional connectivity (FC) of the amygdala and impulsivity by testing for correlation of amygdala FC during performance of a response inhibition task (Stop Signal Task, SST) during fMRI with a self-report measure of impulsive temperament (Barratt Impulsiveness Scale). To determine whether potential findings were specific to the measurement of impulsive action (i.e., response inhibition during task performance), we also conducted the same analysis during the resting state. We hypothesized that amygdala FC to key regions of neural circuitry underlying response inhibition (e.g., right inferior frontal gyrus, RIFG) would be related to impulsivity.
Methods:
Participants who met the DSM-5 criteria for Methamphetamine Use Disorder (MUD) (N=52; 10 females; age range: 24–60 years, M=36.7, SD=8.7) underwent MRI scanning after an average abstinence period of 100 days from methamphetamine use. Among the 52 participants who completed the Stop Signal Task, 36 also underwent resting-state fMRI scans. All participants completed the Barratt Impulsiveness Scale (BIS-11). Image preprocessing was performed using FMRIPREP (23.1.4), and further data cleaning steps were conducted using XCP-D (0.7.5), including the removal of movement-related signals, cerebrospinal fluid (CSF), and white matter (WM) signals (ACompCor: 5 components). Data were bandpass-filtered (0.01–0.08 Hz) and spatially smoothed (FWHM = 6 mm). Whole-brain voxel-wise univariate analyses were conducted using SPM12 to test the effect of BIS sub-scores on functional connectivity (FC) between the amygdala (separately for left and right) and the rest of the brain. Statistical thresholds were set at voxel-height p < 0.001 and cluster-level correction with FDR at p < 0.05.
Results:
Voxel-wise analyses revealed significant FC between right amygdala and the RIFG (pars triangularis) and right inferoparietal cortex, which was negatively correlated with the perseveration factor of the BIS during the SST. No significant findings were observed in analysis of resting state data.
Conclusions:
Amygdala function may have a role during response inhibition that scales with trait-level impulsivity in individuals with MUD. Notably, we did not observe this relationship during the resting state, suggesting context-specific findings. The results suggest potential generation of negative affect during response inhibition especially in highly impulsive individuals, for which inhibition may pose a challenge. Further studies may address whether measures of affect are related to the observed amygdala FC. Moreover, performance measures of perseveration (e.g., post-reversal learning errors) may be used to verify self-report measures. Given the importance of both negative affect and impulsivity as features of MUD, this work provides a potential empirical basis to identify targets for therapeutic neuromodulation.
Disorders of the Nervous System:
Psychiatric (eg. Depression, Anxiety, Schizophrenia) 1
Emotion, Motivation and Social Neuroscience:
Emotion and Motivation Other
Higher Cognitive Functions:
Executive Function, Cognitive Control and Decision Making 2
Modeling and Analysis Methods:
Connectivity (eg. functional, effective, structural)
Keywords:
Addictions
Emotions
FUNCTIONAL MRI
Psychiatric Disorders
Univariate
1|2Indicates the priority used for review
·Figure 1. Regions (RIFG, right inferoparietal) showing a correlation between functional connectivity of the right amygdala during the stop-signal task and self-reported perseveration.