Cannabis relieves pain, but what exactly is pain – and why d we experience it? Let’s take a look…
Understanding the science behind how cannabis relieves pain requires the knowledge of what pain is, and how it operates within the human body. Pain is often described as discomfort associated with an injury or tissue damage. It evolved as a complex mechanism for our species to respond to less than optimal or unsafe conditions quickly and effectively.
Pain functions on a spectrum and most individuals experience it at some point in their lives. However, everyone experiences pain differently, and what may pass as intense for one person may not feel the same for another. Pain is also defined as either acute or chronic.
Researchers and scientists agree that pain stands as the first line of defense against diseases and many underlying conditions. It alerts individuals to damage to the body and assists doctors in making more accurate diagnoses. Its presentation can occur in several different modalities. For example, most pain management researchers suggest that pain can be classified in one of three ways:
Each of these categories can be further defined and described. For example, nociceptive pain is often termed “incident” pain, as it occurs after injurious events such as cuts, burns, bruises, scrapes or sprains. It is by far the most common type of pain that individuals experience. Nociceptive pain is regulated by specialized nerve cells that rest at different areas of the body, including the arms, legs, and back.
When there is an injury, even one as minor as a stubbed toe, the affected tissues are flooded with immune cells. Many of these cells release chemicals that alert receptors in the nervous system. These receptors, called nociceptors, detect certain stimuli and send these impulses through the body to particular areas of the brain. These areas of the brain decipher the impulses as pain. Nociceptive pain is usually quite short-lived; as the injury is resolved, so is the pain.
Neuropathic pain is a term that describes any pain that is chronic or episodic and is often the result of nerve damage from disease or injury. Some sufferers of neuropathic pain have described feeling sharp, throbbing, burning or searing pain along their back or limbs. Unlike nociceptive pain, which is often localized, neuropathy cannot be pinpointed to an exact location. It can be triggered by any number of conditions and diseases, including diabetes, multiple sclerosis, cancer, stroke, HIV or injury to the spinal cord.
Pain that is psychogenic or psychosomatic in nature is often exacerbated or caused by mental or emotional distress. This diagnosis is often made when there is no physical source of pain and patients may be undergoing situations such as job loss, divorce, death of a loved one or any other such stressful event. Persons may report a wide range of physical symptoms.
However, research also suggests that messages from emotional and mental distress may get improperly routed or misinterpreted through nerve cells, causing real physical pain. Other psychological factors that may be the underlying cause can also include depression and anxiety disorders.
Psychogenic pain can be prolonged or chronic, and in this case, it is termed a persistent somatoform disorder. Some researchers suggest that psychogenic pain may also be due to a past, localized injury and that the memory is held in the brain, and boosts pain signals across the body. This is called “pain memory.” This may be especially true of those who suffer from “phantom pain” syndrome.
Phantom pain syndrome often affects those who are amputees. Some amputees describe the pain as if their missing limbs are still there. This may be due to the brain having a sort of “map” of the human body. Though the limb is no longer there or may be severely damaged, the brain has not modified its settings, and the map is retained. Signals are interpreted as coming from the limb and are processed as pain.
Cannabis & Nociceptive Pain Management
Cannabis may mitigate and reduce nociceptive pain. It has been shown to affect the Endogenous Cannabinoid System or ECS, which is responsible for a variety of biological functions in the body – including appetite, immune cell function and the distribution of pain messages. The ECS works primarily in the central nervous system and peripheral nervous system.
Cannabis is made up of two main components: THC and CBD. CBD and THC decrease pain sensations by activating CB1 and CB2 receptors in the nervous system. CB1 receptors are typically featured in the central nervous system and are responsible for movement, memory and the regulation of pain signals. CB2 receptors are mainly found outside the peripheral nervous system and function instead in tissues and organs.
CB2 receptors help to modulate inflammation responses and can cause hyperalgesia, or increased sensitivity to painful stimuli. The activation of these receptors releases key neurotransmitters that disrupt the impulses that would be delivered and translated by the brain. The disruption of these critical signals responsible for pain has made cannabis an ideal subject of research and study in pain management.
Cannabis may also lessen the effect of signals that have already reached specialized centers in the brain. Studies indicate that cannabis may be a safer alternative than the use of opioids, which carries the risk of addiction.
Cannabis & Neuropathic Pain Management
Neuropathy is an often chronic or episodic pain state that many researchers find the most complex and challenging. Neuropathic pain often arises from damaged or injured nerve cells including compressed nerves, herniated discs, and many other debilitating nerve conditions and diseases. Researchers have observed that individuals who experience neuropathy report problems with their quality of life and how they function day-to-day.
The efficacy of cannabis use in pain management has been cited in several studies. In one double-blind study using placebos as control variables, participants reported reduced pain in groups where there were both low and high doses of cannabis use when compared to placebos alone. In another study, participants with chronic, resistant neuropathic pain (pain that was resistant to most conventional treatments) reported a 30% overall reduction in pain as indicated on a visual analog scale.
Some researchers have theorized that cannabis relieves neuropathic pain by reducing the connectivity of nerve cells in areas that process pain, in particular, the dorsolateral prefrontal cortex. This part of the brain serves as the end of the line for the dorsal pathway which interprets how the body should react to certain stimuli. Therefore, cannabis may modify not just the sensation of pain, but how a person experiences it.
Cannabis & Psychogenic Pain Management
Doctors, researchers, and scientists have only recently begun to explore the mind-body connection. This connection is often affected by a number of external factors, including quality of life, finances, and relationships. Emotional and mental stressors are thought to increase or cause any number of physical ailments, including chronic pain. Other factors, including depression, anxiety disorders, and even bipolar disorder can also be possible triggers for prolonged or episodic physiological symptoms.
However, cannabis may be an effective treatment of these kinds of psychogenic pain. Conventional treatments of psychological distress can include antidepressants. In some studies, cannabis has been shown to increase the effectiveness of antidepressants. Cannabis may accomplish this by blocking the absorption of antidepressants at protein-binding sites in nerve cells.
Anecdotal evidence also suggests that cannabis decreases anxiety and insomnia, key features in many psychological pain states. Participants in studies of cannabis use and pain management have reported better sleeping patterns in addition to a decrease in the level of their pain.
Pain management analysts have also turned to cannabis in the treatment of phantom pain sufferers. For many of these sufferers, opioids have provided little relief. No in-depth studies have been completed regarding cannabis and phantom pain syndrome; however, cannabis has been reported as being effective in some cases. Even at low doses, some sufferers have reported taking fewer opiates, returning to work at full capacity and feeling less pain.
Cannabis and Pain: Research Takeaways
Studies have indicated that cannabis may be a promising alternative to opioid use and as a treatment for many different types of pain. Individuals who suffer from neuropathy, injury and even some forms of psychogenic pain syndromes have reported decreased levels of pain and better sleeping patterns along with less anxiety.
It is thought that the components of cannabis, both THC and CBD, are able to mitigate pain sensations by activating CB1 and CB2 receptors in the brain. These receptors are responsible for pain messaging.
However, there have been no definitive statements on cannabis use and its effect on pain management. Researchers agree that more studies need to be done to better assess cannabis and pain modulation. Sufferers are urged to talk with their doctors before utilizing cannabis as a pain-relieving option.
Also, anecdotal evidence suggests that the way in which an individual takes cannabis, the strain, type of cannabinoid used (THC or CBD) and dosage impacts the kind of pain relief they may have. Creating a solid, yet adaptable treatment plan with cannabis may help in the long-term.