Physician bias is one of those barriers. We are more apt to give opioids to the patient dying of cancer pain than to the individual who may look normal but suffering from chronic benign pain. We may be more apt to classify these patients as having psychogenic pain and not want to prescribe the most appropriate pain meds. It is important to understand the type of pain before deciding on the best meds. For example, musculoskeletal pain does well with nsaids or acetaminophen.
Neuropathic pain can respond well to amitryptyline.
Opioids are another class, of course, that can also be used in pain management not responding the above. Strong opioid examples are the morphine or morphine -like drugs. Concern for addiction is much greater than the development of addiction in the population with chronic benign pain. Tolerance to opioid therapy commonly occurs but this usually doesn't equate to addiction. The patient simply may need to get a higher dose to get the pain relief being sought.