Adaptations of the Brain in Chronic Pain With Opioid Exposure I

Inclusion Criteria: * History of low back pain for a minimum of 6 months daily (prior to screening), meeting the Quebec Task Force Classification System symptom categories I-III; * Male or female, age equal or greater than 18 years, with no racial/ethnic restrictions; * Must have a Visual Analog Scale (VAS) pain score ≥ 40 mm (of 100 mm maximum) at the baseline scanning visit (for which 0mm = no pain, and 100 mm = worst pain imaginable); * Must be able to read and speak English and be willing to read and understand instructions as well as questionnaires; * Must be in generally stable health; * Must sign an informed consent document after a complete explanation of the study documenting that they understand the purpose of the study, procedures to be undertaken, possible benefits and potential risks, and are willing to participate; * Must have, on average ≥ 4/10 units of pain intensity over the course of a 1-2 week period prior to the brain scanning visit; * Must be willing to complete daily smartphone/computer app ratings; * Must be on regular opioid or NSAID therapy for at least 3 months prior to randomization (for opioid and non-opioid treatment groups, respectively), which will be up to the clinical investigator's decision. Exclusion Criteria: * Low back pain associated with any systemic signs or symptoms, e.g., fever, chills; * Evidence of rheumatoid arthritis, ankylosing spondylitis, acute vertebral fractures, * fibromyalgia, history of tumor in the back; * Other comorbid chronic pain or neurological conditions; * Involvement in litigation regarding their back pain or having a disability claim or receiving workman's compensation or seeking either as a result of back pain; * Diagnosis of current major depression or psychiatric disorder requiring treatment, or such a diagnosis in the previous 6 months; * Beck Depression Inventory II score of \>28; * Use of therapeutic doses of antidepressant medications at unstable doses (i.e., tricyclic depressants, * SSRIs, SNRIs; low doses used for sleep may be allowed); * Significant other medical disease such as diabetes, congestive heart failure, coronary or peripheral vascular disease, chronic obstructive lung disease, or malignancy; * Uncontrolled hypertension; * Renal insufficiency; * Current use of recreational drugs or history of alcohol or drug abuse; * Any change in medication for back pain in the last 30 days; * High dose opioid prophylaxis, as defined as \> 50mg morphine equivalent/day; * Any medical condition that in the investigator's judgment may prevent the individual from completing the study or put the individual at undue risk; * In the judgment of the investigator, unable or unwilling to follow protocol and instructions; * Evidence of poor treatment compliance, in the judgment of the investigator; * Intra-axial implants (e.g. spinal cord stimulators or pumps); * All exclusion criteria for MR safety: any metallic implants, brain or skull abnormalities, tattoos on large body parts, and claustrophobia; * Pregnancy, or inability to use an effective form of contraception in women of child-bearing age; * Diabetes (type 1 or type 2); * Lactose intolerance; * Allergic reaction to naproxen or any NSAID; * Any untoward reaction to l-dopa or carbidopa.