Grant: Project Grant

Pain is the primary reason individuals seek healthcare, the leading utilization of health care resources, and the most important source of disability among working adults in both Canada and the United-States. The estimated cost of chronic pain to the Canadian society is $6 billion/year in medical treatments and 37 billions/year in loss of productivity. Unfortunately, nearly half of severe pain patients are unable to control their pain. Opioids are among the most frequently prescribed drugs for the management of chronic pain and Canada has the second highest opioids prescription rate per capita. Evidence indicates that up to 20-30% of pain patients misuse opioids and that roughly 10% of them will develop opioid addiction. These addictive opioid therapies have led to an alarming increase in rates of hospitalizations and overdose deaths in North America. Opioid craving (i.e., the subjective desire to consume opioids) is one of the strongest predictors of opioid misuse and addiction among patients with chronic pain. There are reasons to believe that neurobiological factors may be associated with opioid craving, but this has yet to be systematically tested in this population. Previous studies demonstrated that substance use disorders are associated with a dysregulation of the dopaminergic system that dampens the ability to feel pleasure and reduces the motivation to pursue normal activities, contributing to the craving for the drug. This proposal aims at studying the dopaminergic system in chronic pain patients using opioids, especially the one craving their medications. This research will help identify targets for treatment and prevention of opioid addiction among chronic pain patients.