Re-appraisal of negative emotions in cocaine dependence: dysfunctional corticolimbic activation and connectivity

Abstract

Cocaine dependence is associated with pronounced elevations of negative affect and deficient regulation of negative emotions. We aimed to investigate the neural substrates of negative emotion regulation in cocaine-dependent individuals (CDI), as compared to non-drug-using controls, using functional magnetic resonance imaging (fMRI) during a re-appraisal task. Seventeen CDI abstinent for at least 15 days and without other psychiatric co-morbidities and 18 intelligence quotient-matched non-drug-using controls participated in the study. Participants performed the re-appraisal task during fMRI scanning: they were exposed to 24 blocks of negative affective or neutral pictures that they should Observe (neutral pictures), Maintain (sustain the emotion elicited by negative pictures) or Suppress (regulate the emotion elicited by negative pictures through previously trained re-appraisal techniques). Task-related activations during two conditions of interest (Maintain>Observe and Suppress>Maintain) were analyzed using the general linear model in SPM8 software. We also performed psychophysiological interaction (PPI) seed-based analyses based on one region from each condition: the dorsolateral prefrontal cortex (dlPFC-Maintain>Observe) and the inferior frontal gyrus (IFG-Suppress>Maintain). Results showed that cocaine users had increased right dlPFC and bilateral temporoparietal junction activations during Maintain>Observe, whereas they showed decreased right IFG, posterior cingulate cortex, insula and fusiform gyrus activations during Suppress>Maintain. PPI analyses showed that cocaine users had increased functional coupling between the dlPFC and emotion-related regions during Maintain>Observe, whereas they showed decreased functional coupling between the right IFG and the amygdala during Suppress>Maintain. These findings indicate that CDI have dysfunctional corticolimbic activation and connectivity during negative emotion experience and re-appraisal.

Keywords: amygdala; cocaine; connectivity; dorsolateral prefrontal cortex; inferior frontal gyrus; negative emotion; re-appraisal.