Brain Imaging Study on Biomarkers for Chronic Back Pain

Drugs used for managing chronic pain have not proven to be effective and chronic pain continues to cost Canadians $60 billion a year without truly helping those who suffer. The study proposes to investigate the factors related to a person that can enhance or reduce the effectiveness of pain treatments in people suffering with chronic pain. Treatment response to pain killers in a person may be related to their brain, genetics, social, and psychological makeup. The investigators aim to study these factors to identify and develop feasible and robust indicators based on a person's biological makeup (also called biomarkers). These biomarkers will allow doctors and researchers to predict more accurately which treatment and prevention strategies for a particular disease will work in which groups of people. These measures will offer new opportunities for improving treatment such as by tailoring treatment to meet the specific needs of each patient based on his/her biological and psychological makeup. Towards the specific aim, data will first be collected in several experimental domains for studying treatment expectations (cognitive, psychosocial, brain-related, genetic). These 'experimental' data will be compared between chronic back pain (CBP) and healthy participants to yield new understanding of the factors that govern treatment response. At the end of experimental data collection, the investigators will collect data in the 'clinical' domain. Hence, at the end of the experimental sessions, a subset of CBP participants will receive a mock drug (placebo disguised as an approved pain treatment) and another subset will provide pain ratings only and hence serve as a waiting list control for the placebo trial. Data will be studied in steps to understand factors that mediate treatment outcomes and finally the investigators will use advanced computational tools used for big data analysis and aim to identify factors that can be used as biomarkers and precision medicine tools.

Inclusion criteria

Chronic pain participant inclusion criteria:

• 18-75 years of age
• Right-handed
• Meet the classification criteria of chronic low back pain (having low back pain for more than 6 months), as determined by a physician and documented in the participant's medical record.
• At least 4/10 clinical pain on the Brief Pain Inventory Scale on average during the two weeks prior to enrollment
• Comfortable completing (reading and writing) questionnaires and tasks with English language instructions

Healthy participant inclusion criteria:

• 18 - 75 years of age
• Right-handed
• Comfortable completing (reading and writing) questionnaires and tasks with English language instructions

Exclusion criteria

Chronic pain participant exclusion criteria:

• History of cardiac, respiratory, or nervous system disease that may interfere with participation in the study or cause heightened potential for adverse outcome. For example: asthma or claustrophobia
• Presence of any contraindications to MRI scanning. For example: cardiac pacemaker, metal implants, fear of closed spaces, pregnancy

Healthy participant exclusion criteria:

• Acute or chronic pain
• History of cardiac, respiratory, or nervous system disease that, in the investigator's judgment and by asking the participant about their comfort level and ability, precludes participation in the study because of a heightened potential for adverse outcome. For example: asthma or claustrophobia
• Presence of any contraindications to MRI scanning. For example: cardiac pacemaker, metal implants, fear of closed spaces, pregnancy