Emotion regulation deficits in regular marijuana users

Abstract

Effective regulation of negative affective states has been associated with mental health. Impaired regulation of negative affect represents a risk factor for dysfunctional coping mechanisms such as drug use and thus could contribute to the initiation and development of problematic substance use. This study investigated behavioral and neural indices of emotion regulation in regular marijuana users (n = 23) and demographically matched nonusing controls (n = 20) by means of an fMRI cognitive emotion regulation (reappraisal) paradigm. Relative to nonusing controls, marijuana users demonstrated increased neural activity in a bilateral frontal network comprising precentral, middle cingulate, and supplementary motor regions during reappraisal of negative affect (P < 0.05, FWE) and impaired emotion regulation success on the behavioral level (P < 0.05). Amygdala-focused analyses further revealed impaired amygdala downregulation in the context of decreased amygdala-dorsolateral prefrontal cortex functional connectivity (P < 0.05, FWE) during reappraisal in marijuana users relative to controls. Together, the present findings could reflect an unsuccessful attempt of compensatory recruitment of additional neural resources in the context of disrupted amygdala-prefrontal interaction during volitional emotion regulation in marijuana users. As such, impaired volitional regulation of negative affect might represent a consequence of, or risk factor for, regular marijuana use. Hum Brain Mapp 38:4270-4279, 2017. © 2017 Wiley Periodicals, Inc.

Keywords: amygdala; marijuana use; negative affect; prefrontal cortex; reappraisal.

Figure 1

Difference in mean reappraisal success between controls and marijuana users. Relative to controls, marijuana users displayed impaired emotion regulation success during reappraisal of negative stimuli. Reappraisal success = mean arousal “spontaneous_negative” − mean arousal “distance.” Error bars indicate SEM. * significant at P < 0.05.

Figure 2

Neural differences between controls and marijuana users. (a) Greater fMRI activation during reappraisal in marijuana users relative to controls. P _FWE < 0.05, cluster level inference. (b) Peak coordinates of greater activation during reappraisal in marijuana users relative to controls. (c) Regions of weaker connectivity during reappraisal of negative stimuli in marijuana users relative to controls. P _FWE < 0.05.

Figure 3

Association between craving and reappraisal success in marijuana users. Successful emotion regulation of negative stimuli decreases with higher subjective craving. (x) Reappraisal success = mean arousal “spontaneous_negative” − mean arousal “distance.” (y) CCS‐7 score. r = −0.459, P = 0.028.