Left ventromedial prefrontal cortex inhibitory rTMS as an anti-stress intervention in opioid use disorder: Trial design

Background

In people with substance use disorders (SUDs), stress-exposure can impair executive function, and increase craving and likelihood of drug-use recurrence. Research shows that acute stressors increase drug-seeking behavior; however, mechanisms underlying this effect are incompletely understood. The Competing Neurobehavioral Decisions System theory posits that persons with SUDs may have hyperactive limbic reward circuitry and hypoactive executive control circuitry.

Objective

To investigate how inhibitory repetitive transcranial magnetic stimulation (rTMS) targeting the left ventromedial prefrontal cortex (vmPFC) may alter stress-induced executive dysfunction, emotion dysregulation, and drug-seeking in people with opioid use disorder.

Methods

We will examine effects of a psychological stressor combined with inhibitory (1Hz) left vmPFC rTMS in participants (N = 24) receiving opioid agonist treatment. Participants undergo guided imagery of autobiographical stressors paired with 10 sessions of active vmPFC rTMS vs. sham (within-subject randomized crossover). Stress-induced dysfunction will be indexed with cognitive (e.g., executive function), affective (e.g., emotional arousal), and behavioral (e.g., opioid-seeking) measures pre- and post-rTMS. To confirm changes are associated with altered neural activity in targeted regions, we will measure event-related potentials during key tasks using EEG. We hypothesize that stressors will increase executive dysfunction, emotion dysregulation, and drug-seeking, and that left vmPFC inhibitory rTMS will decrease limbic activation, which could translate to reduced craving and drug-seeking.

Conclusion

Our findings should offer insights into how neural networks modulate drug-seeking and associated dysfunctions in people with SUDs. The results of this and similar studies can advance theory and neuromodulation interventions for people with SUDs.