Cannabis Patient Care - December 2021

Cannabis Patient Care December 2021

Issue link:

Contents of this Issue


Page 10 of 39

11 december 2021 | cannabis patient care research focus an association between the event and that context. In other words, the PTSD is "anchored" to that context, and, thereafter, whenever those same sights, sounds, or smells reappear, they trigger flashbacks of the event, together with the associated fear. This phenomenon is called fear conditioning. Most people who are conditioned by a certain trigger will eventually become deconditioned, that is, experience fear extinction. Extinction generally occurs when the trigger appears often enough in the absence of the event that initially caused the fear conditioning. Unfortunately, many people who suffer from PTSD are unable to achieve fear extinction. Forms of behavioral therapy may help decondition fear in those who suffer from PTSD, but these therapies are often not fully effective in bringing long-term relief (5). Experiencing fear, fear conditioning, and fear extinction all take place in a region of the brain called the amygdala, which is responsible for acquiring, storing, and forgetting memories. People who suffer from PTSD develop "hyperactivity of the amygdala." Researchers have also shown that the amygdala contains ECS receptors and that those ECS receptors are less active in people who sufferer from PTSD (5,8–10,13,14). This un- deractivity of the ECS in the amygdala of people with PTSD suggests that cannabis should be effective in helping victims extinguish fear associated with traumatic memories. In sum, PTSD victims have been conditioned to associate a particular trigger with the memory of an event, together with the fear experienced during that event. This activity takes place in the brain's amygdala, where ECS activity has been shown to occur, but is lacking in PTSD victims. As such, canna- bis may help enhance ECS activity in the amygdala and extin- guish the fear associated with the trigger. Flashbacks Even if cannabis can help people who suffer from PTSD to extinguish the fear associated with a trigger, the memory of the traumatic event often still remains to haunt the victim. Researchers have identified a specific region of the brain, the hippocampus, as being involved in memory learning, stor- age, and retrieval, and also as being overactive in sufferers of PTSD (8,10,13). Another function of the hippocampus is to ac- tively manage memory extinction, that is, the active pruning by the brain of "unnecessary" memories (15). So the region of the brain responsible for storing and retrieving memories is not only overactive in people with PTSD, but it is also unable to forget undesirable memories. At the same time, researchers have found ECS receptors in the hippocampus and have concluded that cannabis may help with the extinction of aversive memories in people who suffer from PTSD (7,8,11,14,16). Noteworthy is the fact that PTSD has been "persistent and resistant to pharmacological interventions," due to the lack of therapeutics to help with memory extinction (15). This suggests that cannabis may be a valuable new therapeutic that may very well bring new-found relief to PTSD patients. Sleep Disorders It is well-known that people with PTSD suffer from sleep prob- lems, in particular delayed onset of sleep and greater numbers of awakenings during the night (8). It has been shown that cannabis (specifically, THC) can help decrease REM sleep, the stage in which nightmares occur, while enhancing deep sleep, the regenerative and restorative stage of sleep (8,11). Cannabis should thus be able to help address sleep problems in people with PTSD. Stress and Anxiety Any threat to our physical or emotional well-being creates stress, which then triggers our primal fight-or-flight response. Our body's response to threats is moderated by the hypothalamic-pi- tuitary-adrenal (HPA) axis located in our central and periph- eral nervous systems (17). When we experience stress, the HPA secretes hormones that prepare our bodies to deal with those threats; for example, our heart rate and blood pressure both increase, while our digestive, reproductive, and immune system functioning decrease. Normally, hormones secreted by the HPA axis also serve as feedback mechanisms to shut down the stress response after the threat has passed. However, PTSD impairs the feedback mechanism, leading to constant states of arousal (18). Animal studies have shown that chronic stress is associated with low levels of a certain endocannabinoid that is produced within our bodies, called AEA. Among other functions, AEA helps to alleviate stress (9). Studies have also shown that in- creasing the levels of cannabinoids in our bodies leads to re- duction in levels of anxiety-promoting hormones, which then reduces anxiety (8,9). There is thus a clear mechanism for can- nabis to reduce stress and anxiety in patients with PTSD. Depression Depression is a common comorbidity associated with PTSD (6,8,10). Low levels of ECS activity have been associated with depression (10), and as mentioned, victims of PTSD tend to exhibit low levels of ECS activity. Next, researchers have also linked depression to low levels of serotonin, a neurotrans- mitter in the body (9); indeed, primar y treatments for de- pression, SSRIs, ser ve to increase levels of serotonin. Finally, researchers have shown that cannabinoids enhance sero- tonin levels in the body, thereby reducing symptoms of de- pressions (8,10). Taken together, the research thus suggests that cannabis can help address depression in PTSD suffers both directly, by increasing ECS activity in the body general- ly, as well as indirectly, by increasing serotonin activity. Clinical Studies on Cannabis for PTSD There have been a number of clinical studies of cannabis use for PTSD. One systematic review of clinical studies of cannabis

Articles in this issue

Links on this page

view archives of Cannabis Patient Care - December 2021 - Cannabis Patient Care December 2021