Prescription opioid misusers exhibit blunted parasympathetic regulation during inhibitory control challenge.

Abstract

RATIONALE\nAmong opioid-treated chronic pain patients, response inhibition deficits in emotional contexts may contribute to opioid misuse.\n\n\nOBJECTIVES\nUsing high-frequency heart rate variability (HF-HRV) to index-impaired response inhibition, we examined associations between opioid misuse and response inhibition in emotional and neutral contexts in a sample of opioid-treated chronic pain patients.\n\n\nMETHOD\nChronic pain patients taking opioid analgesics (N\u2009=\u200997) for ≥\u200990\xa0days completed an Emotional Go/NoGo task that presented an inhibitory control challenge in the context of neutral, opioid, negative affective, and positive affective background images while HF-HRV was computed. Opioid misuse and craving were assessed. Using a validated cut-point on the Current Opioid Misuse Measure, participants were classified as opioid misusers or non-misusers. Opioid misuse was examined as a predictor of behavioral and HF-HRV metrics of response inhibition.\n\n\nRESULTS\nNegative affective and opioid images elicited more errors of commission (p\u2009=\u2009.002, η2partial\u2009=\u2009.16) and slowed reaction times (p\u2009=\u2009.045, η2partial\u2009=\u2009.09) compared to neutral and positive affective images, respectively. Though no between-group behavioral differences were observed on the task, opioid misusers exhibited significantly blunted phasic HF-HRV during the task relative to non-misusers (p\u2009=\u2009.027, η2partial\u2009=\u2009.11). HF-HRV during the task was significantly inversely associated with opioid craving. It was not clear whether these autonomic findings reflected a durable phenotypic difference between groups or between-group differences in opioid dosing and withdrawal.\n\n\nCONCLUSION\nReduced parasympathetic regulation during inhibitory control challenge may indicate heightened opioid misuse risk among opioid-treated chronic pain patients.