The opioid crisis continues to devastate communities across the nation, raising health, economic, and social concerns.
According to the Public Health Agency of Canada, there were over 2,000 deaths linked to opioid misuse between January and June in last year alone. In 2017, Ontario saw a 73 per cent hike in emergency room visits related to opioid overdose. According to the government of Canada, this trend reflects the mass prescribing of opioid medication by physicians and the widespread access to illicit drugs.
Regardless of the cause of the crisis, the chronic use of opioids can cause noticeable structural changes to the brain. The underlying neurobiology of opioid addiction can help us better understand the extent of the crisis and possibly discover novel solutions to this growing concern.
The body’s natural painkillers, endorphins, are usually released in response to pain. But, when pain exceeds our body’s self-treating capacity, opioids like fentanyl and oxycodone can be taken to combat it. These drugs work by mimicking our innate pain-relieving system and by directly intercepting the signals that carry pain.
Opioids bind to specialized receptors that activate the brain’s reward system. This causes a rush of dopamine, the “feel-good” chemical that is also released as we sip our grande extra-sweet full-of-fat caramel macchiato. This burst of pleasure—and the accompanying pain relief—is reinforced and stored in memory as a positive experience.
Problems arise when opioids are taken merely for the pleasurable experience—or high—rather than to reduce substantial pain.
Because of the existing memory component, users of the drug associate the high with various places, people, and events. When they encounter these things, individuals can experience intense cravings for the drug, making it especially difficult to discontinue drug use.
Over time, the high is no longer the sole driving force of the behavior—individuals may feel mentally and physically compelled to take the drug.
Once the brain detects the excess dopamine caused by prolonged opioid use, the specialized receptors become less responsive to the drug. Therefore, individuals often require larger doses to attain the same effect, demonstrating the tolerance they have built towards the drug.
If tolerance is reached, individuals can become increasingly dependent on the drug and rely on it to feel normal. They also often continue drug use in order to evade symptoms of opioid withdrawal. These symptoms—which include depression, nausea, muscle cramps, and intense opioid cravings—actually increase the likelihood of relapse and continue to drive drug-seeking behaviors.
To overcome this catch-22, effective treatment and education are key. Naloxone, a drug that reverses the effects of opioid overdose, has been used by emergency and health-care aids for several decades. In 2016, in responding to the opioid crisis, Health Canada allowed pharmacies to sell naloxone kits without requiring a prescription. Some provincial governments even cover the cost of the drug.
While naloxone does help prevent opioid-related fatalities, it does not necessarily reduce drug use. A common treatment for opioid dependence is methadone, an opioid medication with long-lasting and slow-releasing effects, unlike more addictive opioids like morphine or heroin. While it may seem ironic, methadone treatment has actually been effective, to a certain degree, in reducing relapse rates, according to Canadian Addiction Treatment Centres (CATC).
Because the effects of methadone can persist for several days, it reduces the perpetual cravings and the sense of compulsion that can often reverse progress. Individuals can then focus on improving their lifestyle habits and reintegrating themselves into the community.
However, controversy does exist regarding the use of methadone treatment because it still carries the risk of dependence and overdose.
Many alternative treatments and education programs, such as counselling and behavioral therapy, are also available and offer a well-rounded approach to opioid abuse.
The opioid crisis is a nation-wide problem in need of attention and resources. By acknowledging its root complexity—including the underlying neurobiology—we can help eliminate the stigma surrounding opioid abuse and become better equipped to find practical solutions.
Graphic by Paloma Callo
