Reregulation of cortisol levels and sleep in patients with prescription opioid use disorder during long-term residential treatment

•Prescription opioid dependent patients assessed in long-term residential treatment.•Patients had elevated basal cortisol and reduced total sleep time versus controls.•Total sleep time, cortisol levels in first 4 weeks did not predict treatment outcome.•Patients whose sleep, cortisol remained disrupted 9–10 weeks more likely to relapse.•Reregulation of sleep & cortisol linked to drug free status 120 days post-discharge. Research has demonstrated that hypothalamic-pituitary-adrenal (HPA) axis function and sleep patterns are dysregulated in patients diagnosed with opioid use disorder (OUD). It is unclear whether and/or when cortisol and sleep might re-regulate over time, and, whether re-regulation is associated with abstinence following discharge from residential treatment. The current study evaluated changes in sleep and basal cortisol levels in prescription OUD patients in residential treatment, and the association between these measures and treatment outcome following discharge. As part of a larger study, 55 participants with prescription OUD provided two days of salivary cortisol samples and 12 consecutive nights of sleep actigraphy between days 19–30 of residential treatment (Time Point 1; TP1). Thirteen of the original 55 participants remained in residence and repeated the measures between days 60–72 (Time Point 2; TP2). Thirty-seven healthy controls (HC) provided baseline measures (TP1) of salivary cortisol and sleep. Treatment outcome data, abstinence vs relapse, were established at 120 days following discharge. Prescription OUD patients had higher cortisol levels and lower total sleep time (TST) than HC at TP1. At TP2, TST and cortisol levels no longer differed from HCs in the subgroup of patients who remained abstinent following discharge after TP2. Individuals whose cortisol and TST did not change from TP1 to TP2 were more likely to relapse following discharge from residential treatment. Re-regulation of TST and cortisol levels while in residential treatment was associated with better treatment outcome following discharge for prescription OUD patients.