Increased Sensitivity to Pain Caused by Opioids in People Who Have Abused Prescription Opioids

Inclusion Criteria: 1. Be between the ages of 21 and 65 years of age. 2. Have a DSM-IVR diagnosis (used through 10/1/2014) of prescription opioid abuse or dependence disorder or a DSM-5 diagnosis of opioid use disorder. 3. Be enrolled and compliant in Suboxone or methadone treatment and on a stable dose \[Suboxone (6-24mg/day); of methadone (60-120mg/day)\] x at least 10 days. 4. Provide urine sample absent of any non-prescribed drugs of abuse at screening. 5. Screening cold-pressor pain tolerance \< 70 seconds 6. Have chronic lower back pain or arthritis pain (duration six or more months). 7. Be otherwise in good physical health, or in the case of a medical condition needing ongoing treatment, be in the care of a physician who is willing to take responsibility for such treatment. The same conditions apply in cases of patients with a psychiatric disorder needing ongoing treatment. 8. Be agreeable to and capable of signing an informed consent. Exclusion Criteria: 1. Have known sensitivity to pregabalin or gabapentin. 2. Potential participants must not be taking the following medications: pregabalin or gabapentin, tiagabine, vigabatrin, valproate, phenobarbital or primidone for the treatment of epilepsy; SNRI or TCA antidepressants; baclofen; or carbamazepine, oxycarbazepine or lamotrigine for the treatment of chronic pain. 3. Currently be substance dependent on alcohol, benzodiazepine, methamphetamine, cocaine or other drugs of abuse (except nicotine). 4. Have any acute medical condition that would make participation medically hazardous, (e.g., acute hepatitis, unstable cardiovascular disease, liver or renal disease) or have liver enzyme values (AST or ALT) greater than 5 times normal range. 5. Be acutely psychotic, severely depressed and in need of inpatient treatment, or an immediate suicide risk. 6. Have a neurological or psychiatric illness (i.e., schizophrenia, Raynaud's disease, urticaria, stroke) that would affect pain responses. 7. Be currently taking opioid analgesic medication for a painful condition on a regular basis. 8. Be a nursing or pregnant female, or a female or male who does not agree to not become pregnant or father a child during the course of, and six months following completion of the study. If a subject becomes pregnant or fathers a child during the study, they must immediately notify the study investigator. 9. Have a history of heart disease, stroke, liver or kidney disease, epilepsy or acute hepatitis, or currently have a pacemaker…