This project will determine whether enhancing endogenous opioids (via SMT or MT) permits achieving desired levels of analgesia with lower dosages of opioid analgesics, and fewer side effects and abuse-relevant drug effects. This X year project will test study hypotheses in a sample of 240 chronic low back pain patients. The study will have 2 key elements: 1) a randomized, controlled SMT or MT in chronic pain (CP) patients completing daily take home exercises and 2) laboratory evoked thermal pain protocols pre- and post- therapy, permitting the quantification of EO function and the examining of treatment-induced changes in EO function (placebo vs. naloxone).
The study will employ a mixed between/within-subjects design using double-blinded and placebo-controlled administration of the opioid antagonist (naloxone). The study will use a 8 week supervised MT or SMT manipulation with subjects randomly assigned to one of the groups. All participants will undergo 4 laboratory pain-induction sessions in total. 2 during the pre-treatment phase, and 2 post-treatment. The laboratory sessions are identical. Each laboratory session will be roughly 2-3 days apart and the first 2 laboratory sessions will occur prior to the randomization to the treatment condition.