Opium has been used for thousands of years and is still available today in various forms. In the early twentieth century in the United States, physicians became aware of the pain-relieving qualities of the substance and eventually learned of its effectiveness in treating acute and terminal cancer pain. At that point, physicians thought that the addiction rate in this group, which was low, would be repeated in patients with chronic pain and they began to prescribe opioids to that patient group as well. This, however, wasn’t the case. This review, which looks at several studies of pain relief and addiction, tries to explain the multidimensional aspect of addiction as it relates to pain relief.
After many studies, researchers have concluded that drug addiction is a chronic neurobiologic disease that results from repeated exposure to the addictive drug. Because much of the addiction is the reward the body feels after consuming the drug, the changes that occur in the brain are not just from the drug, but from the behaviors that the person associates with getting the drug, consuming it, and the resulting sensation.
There are three domains that contribute to addiction: psychosocial, drug, and genetic. In the psychosocial domain, researchers have determined that there are many factors, such as depression, anxiety, personality disorder, and atypical stress response, among others. In the drug domain, the initial part is the stimulation of the reward circuitry and how the drug is taken; in the maintenance part, there is the tolerance and dependence that may result, and the enduring adaptations of the neurons associated with lifelong craving; and finally, the withdrawal and abstinence part that is the anhedonic (loss of feeling) state and negative reinforcement. In the genetic domain, we find family history of addiction, personality disorder, genetic changes that might affect impulse control and risk taking behavior, and atypical stress response.
There are stages that result in addiction to drugs:
1- Initiation of drug use.
2- Intermittent use.
3- Regular use.
4- Dependence or addiction.
5- Withdrawal.
7- Perhaps stopping the drug use.
6- Frequently, relapse.
Chronic pain, which can be hard to treat, is considered to be a pain that lasts for at least three months, maybe longer according to different guidelines. There’s a common thread between people with chronic pain and mental disorders, such as depression, anxiety, substance use disorders, and personality disorders. According to one study, between 18 percent and 32 percent of patients with chronic back pain also had major depression during the treatment period. The average US rate for depression among the general population is only 5 percent.
It’s not always easy to determine if someone has become addicted to a prescribed medication, like an opioid. Some researchers have tried to determine guidelines, but they have not been formally adopted by any group. Despite all the research, the medical community is still uncertain regarding the frequency of opioid dependency with chronic pain. Several studies uphold the idea that the pain actually works against the opioids, preventing true addiction.
The way the drug is metabolized, or absorbed and broken down in the body, and how quickly this happens plays a role in its addictive properties. Drugs with a rapid onset have a higher potential for addiction, for example. For this reason, the longer-acting opioids are now being used more for the management of chronic or cancer pain.
The authors conclude that the initial idea that addiction would be rare among patients with chronic pain is incorrect and that problematic and attention-seeking behaviors can and do occur in a sub-group of patients with chronic pain. The development, or clinical progression, from a patient with chronic pain to a patient with chronic pain who is addicted to an opioid differs very much from people who use the drug illegally and those who use it for pain relief. It appears to be a much more subtle progression and is more difficult to identify.
More research needs to be done in this field. Researchers need to find a better way of identifying patients with chronic pain who would be at risk of becoming addicted and to find medications that would not have addictive qualities but still offer adequate pain relief.