Abstract
BACKGROUND/OBJECTIVES: Chronic pain is an opioid use disorder (OUD) treatment barrier and associated with poor outcomes in OUD treatment including relapse. Fibromyalgia is a chronic pain condition related to central nervous system substrates that overlap with the brain disease model of OUD. We know of no studies that have looked at non-treatment seeking individuals, to see if fibromyalgia might represent a barrier to OUD treatment. Given many non-treatment-seeking individuals previously attempted recovery before experiencing relapse, and chronic pain is a known precipitant of relapse, fibromyalgia might be a currently unappreciated modifiable factor in OUD relapse and, potentially, a barrier to treatment reengagement among those not currently seeking treatment. This study aimed to determine if fibromyalgia is associated with greater odds of agreeing that 'I have tried to stop using opioids before, but pain caused me to relapse' among non-treatment seeking individuals with OUD. METHODS: This cross-sectional study recruited non-treatment-seeking individuals with OUD (n = 141) from a syringe service program. Ordinal logistic regression was used to determine if the presence of fibromyalgia increased the odds of agreement with prior pain-precipitated relapse. RESULTS: Fibromyalgia was identified in 35% of study participants and associated with 125% greater odds of strongly agreeing that pain had previously caused them to relapse, even after accounting for relevant covariates, including age, sex, depression, anxiety, OUD severity, and pain severity. CONCLUSIONS: This study provides early evidence that the presence of fibromyalgia may be associated with increased odds of pain-precipitated OUD relapse.