Do you feel alright? Attenuated neural processing of aversive interoceptive stimuli in current stimulant users

Inability to appropriately process afferent interoceptive stimuli may contribute to initiation and/or escalation of substance use. An aversive interoceptive stimulus probed neural processing in problem stimulant users (PSU; n=19), 18 desisted stimulant users (DSU; n=18), and healthy comparison subjects (CTL; n=21). Participants completed a continuous performance task while they anticipated and experienced 40cm H2O/L/sec inspiratory breathing loads during fMRI. PSU exhibited lower left dorsolateral prefrontal cortex and inferior frontal gyrus (IFG) activation than DSU and CTL across trials. Greater lifetime drug use due to stimulants was also linked to lower activation in these regions. In addition, PSU displayed lower right IFG and insula activation during breathing load than DSU and CTL. Findings suggest that transition to stimulant use disorders is marked by weakened attentional salience of aversive stimuli.