Researchers have identified the species through the passive monitoring of user-generated data from medical cannabis patients and amounts of marijuana that seem to be effective in relieving the symptoms of stress, anxiety, and depression. The results could allow a more detailed study of the best strains for specific conditions. However, the data also point to the danger of long-term use of marijuana for the treatment of depression symptoms.
The study, published this week in the Journal of Affective Disorders by researchers at Washington State University, is based on data from a medical cannabis app called Strainprint that helps patients track the severity of symptoms of medical cannabis use can. Prior to this, users will provide detailed information about the marijuana strain used, including the selection of specific products from a list of those marketed by licensed cannabis dealers in Canada. Health Canada has the strictest production and quality control guidelines for its products. However, if a patient uses a product that is not on the list, they can manually enter information about the strain, including the cannabinoid content.
Researchers reviewed data from nearly 1
The sessions were based on whether users are trying to reduce the symptoms of stress, anxiety or depression. The researchers then looked for symptom-level changes (on a self-reported scale from none  to the most severe ), gender-specific effects, the percentage of Δ 9 tetrahydrocannabinol (THC) and cannabidiol (CBD) in the trunk, dose effects and changes in symptoms over time.
For anxiety, researchers found a significant reduction in ratings of overall anxiety symptoms, with 93.5 percent of the sessions pursued to alleviate anxiety symptom. In general, women showed a greater decrease in symptoms than men. Two or more puffs were most effective at reducing symptoms. One was relatively less effective, but two traits were as effective as 10 users, according to users. However, neither THC nor CBD levels seemed to play a role in relieving symptoms. The patients reported relief, regardless of the two levels. Over time, users reported a short-term relief, but they saw no improvement in their overall symptoms. That is, cannabis use did not prevent, slow or increase future anxiety.
Researchers also found significant symptom reduction for stress, with 93.3 percent of sessions facilitating it. But just as with anxiety, baseline stress did not seem to decrease with the use of marijuana over time. There were no gender differences for the effects. The researchers found a slightly positive linear relationship between the number of trains and the symptom relief, with 10 trains being the most effective.
The largest reductions in stress symptoms were found when using products with high THC concentrations and high CBD values. (They defined "high" as an amount of at least one standard deviation above the mean in the products used, while "low" was defined as having at least one standard deviation below this mean.) The products used for stress had an average THC content of 16, 53 percent, with a standard deviation of 9.97 and an average CBD content of 2.97 percent, with a standard deviation of 8.36 (see table in the gallery above). In other words, the products most effective for stress reduction had THC levels at or above about 26.5 percent and CBD levels at or above 11 percent. High THC / low CBD, low THC / high CBD, or low TCH / low CBD products all exhibited about the same efficacy as lower than those of the high THC and high CBD products.
For the depression, the researchers also found that inhalation sessions relieved the symptoms in the short term. About 89 percent of the sessions resulted in immediate symptom relief. There were no gender differences for these effects, and there were no dose effects. That is, a train appeared to be as effective as 10 or more trains, suggesting that "microdosing" might be effective for depression symptom relief.
The most effective products for depression have been those with relatively low THC levels and high CBD levels. Specifically, the most efficacious products had THC levels at or below about five percent and CBD levels at or above about 10 percent.
Along with results from exercise data, researchers noted:
Non-medical cannabis The market is currently dominated by the sale of high THC cannabis products, but these results suggest that CBD is an important component of cannabis and that cannabis users should seek cannabis with CBD levels of 10 percent or more.
Finally, the researchers found that while marijuana improved depression symptoms at short notice, patients did register more severe symptoms of depression over time. This suggests that marijuana may increase or aggravate long-term depressive symptoms, which has been seen in some antidepressant medications.
The researchers speculate that this negative effect may be due to the way marijuana affects the endocannabinoid system of the body. Some data suggest that chronic cannabis use blocks chemical messenger receptors known as CB1 receptors in areas of the brain that are associated with affective disorders. And such a CB1 blockade has been associated with depression. However, the researchers found that the abstinence of cannabis for a few days would probably reverse a blockage.
Overall, the study must be continued with blinded, randomized, placebo-controlled trials to verify the results. Self-reported data can be unreliable, as well as product listing of THC and CBD content. The study also did not consider or control the dozens of other cannabinoids in marijuana that could have a health impact. After all, those who use a medical cannabis app are likely to be the most likely to benefit from cannabis, and are therefore not necessarily representative of total patient pools. That said, the researchers argue that home use and the data are a "naturalistic" study of marijuana treatments that may be superior in some aspects to laboratory studies. Since app users did not know that their data was being used for the study (although they had agreed to it), the data provides a real insight into their experiences.
Journal of Affective Disorders 2018. DOI: 10.1016 / j.jad.2018.04.054 (About DOIs).