All Scientific Studies on Cannabis in 2022

Research into the independent effects of THC and CBD remains the focus of most studies on cannabis. However, there is growing interest in commercially available cannabis products, whole-plant extracts, and the effects of terpenes on brain function. Here are some notable studies on cannabis from 2022.

For several years now, Israeli scientists have been conducting clinical trials that show promising results for CBD and THC 20:1 hemp oil in the treatment of many secondary symptoms of autism spectrum disorders. This has allowed people with autism to experience benefits such as: 

• improved sleep, 
• reducing anxiety, 
• reducing tantrums 
• and a reduction in self-harm.

The goal is not to cure autism, but to facilitate greater engagement and promote better life skills so that children can eventually become more independent.
 

The results of these clinical trials show that cannabis also enhances basic social communication skills. It also improves children’s and adolescents’ ability to perform daily tasks such as getting dressed, eating, and washing themselves. It is important to note that these benefits do not extend to other underlying symptoms, such as restricted and repetitive behaviors. However, this study highlights cannabis’s potential to improve the quality of life for people with autism spectrum disorders.

Communication between different regions of the brain changes with age. This contributes to memory problems and cognitive decline associated with aging. Researchers in Colorado used functional neuroimaging to assess how regular cannabis use among people over 60 alters communication between several areas of the brain that tend to decline with age.
 

They found that older adults who regularly used cannabis had stronger communication patterns between three brain regions—the hippocampus, the parahippocampal gyrus, and the cerebellum—compared to older adults who did not use cannabis. The stronger connectivity among older cannabis users was similar to that of much younger non-users. This suggests that cannabis may have protective effects against certain age-related declines in brain function.
 

These results are not causal in nature. This was not a randomized, controlled trial. However, this is one of the first pieces of evidence in humans that replicates the observations made in studies conducted on rodents. Consistent with these observations, small amounts of cannabis consumed regularly protect against age-related changes in the brain and cognitive decline.

Commercial cannabis products are typically labeled with THC and CBD content to provide a predictive measure of how they will produce effects and impact when consumed. It turns out that this information is not sufficient for an accurate prediction.
 

A recent study found that oral ingestion of an oil labeled "Indica" reduced the amount of effort animals were willing to exert to obtain a large reward. Basically, it made them lazy. In contrast, the "Sativa" oil, even though it had the same THC and CBD content, had no effect.

These findings suggest that THC and CBD levels and the indica and sativa classifications are not the only factors to consider when predicting the effects of cannabis use. Other minor cannabinoids and terpenes are also important.

It is said that CBD mitigates the negative effects of THC. Products with a higher CBD-to-THC ratio are therefore marketed as having fewer of the negative effects associated with THC. Researchers conducted a double-blind study involving 46 cannabis users and ultimately found that this hypothesis may be inaccurate.

In their studies, cannabis flowers vaporized using a Volcano and containing CBD ratios of 1:1, 2:1, or 3:1 per 10 mg of THC showed no difference in effects. The CBD level also did not affect the effects of THC, including:

• the feeling of joy,
• memory problems,
• an increase in the pleasure derived from music and chocolate,
• or the effects on a range of physiological parameters, including blood pressure and heart rate.

These findings suggest that adding CBD to THC products at typical recreational levels may not protect against some of the harmful effects of THC. Even higher CBD:THC ratios may be effective. However, the safest strategy for avoiding the potentially adverse effects of THC is to limit the dose rather than mask it with CBD.

A recent study by Arianne Wilson-Poe showed that terpenes have a subjective influence and determine the appeal of a cannabis flower or smoking product. The researchers tested the appeal of a cannabis-based product with varying THC concentrations (from less than 0.3% to more than 30%) among nearly 300 participants during thousands of consumption sessions.

Given the increase in THC potency in products on the market, one would expect THC potency to be directly correlated with the product’s overall appeal. But this is not the case—there was no relationship between THC potency, total cannabis dose, or total THC dose and subjective appeal. On the contrary, only the aroma derived from terpenes was directly correlated with participants’ attractiveness ratings.

Consequently, a product’s smell is a better predictor of enjoyment than its THC content. These findings highlight the importance of terpenes in product quality and suggest that you don’t have to get too high to have an enjoyable experience.

A randomized, placebo-controlled study showed that medical cannabis oil improved both the duration and quality of sleep in a group of patients with clinically diagnosed insomnia.

The study involved a total of 29 participants. They were randomized to receive either a placebo or an active oil containing 10 mg/mL of THC and 15 mg/mL of CBD over a two-week period.

According to the article, participants kept a diary to assess their tolerance, and efficacy was measured by salivary melatonin levels at midnight, validated questionnaires, and a Fitbit sleep tracker.
 

Cannabis oil improved both the duration and quality of sleep. Light sleep increased by 21 minutes per night compared to the placebo. And overall sleep quality improved by up to 80% in the treatment group.

The authors concluded that the oil was "well tolerated" and that 60% of the participants were no longer classified as having clinical insomnia at the end of the trial period.

Cannabis use disorder is defined as the continued use of cannabis despite adverse consequences, resulting in clinically significant impairment or distress. It is estimated that this disorder affects up to 13 million people worldwide.

In a randomized clinical trial, researchers evaluated whether a four-week course of CBD treatment affected cognitive function in people with cannabis use disorder. Seventy participants were randomly assigned to receive a placebo, 400 mg, or 800 mg of CBD. The researchers concluded that although CBD had no effect on delayed verbal memory or overall cognitive function, a daily dose of 800 mg might “improve working memory performance.”

CBD has grown in popularity among athletes because it is no longer considered a banned substance by the World Anti-Doping Agency.
 

A narrative review of existing research concluded that CBD has “the potential to become a suitable supplement that could improve muscle recovery.” In animal studies, CBD was shown to effectively increase the expression of metabolic regulators in the muscles of obese mice. Meanwhile, CBD treatment in rodents reduced muscle inflammation after exercise in a model of muscular dystrophy.

The authors state that in humans, some evidence suggests that taking CBD improves muscle recovery and performance, although the doses vary widely.

Real-world data from the UK Medical Cannabis Registry provide insight into the effects of medical cannabis products on patients with IBD.
 

Seventy-six patients were enrolled in the case series, and outcomes were assessed at one month and three months using a series of validated questionnaires.
 

The mean baseline SIBDQ score improved at one month and three months. Quality of life, anxiety, and sleep scores also improved after three months. Just over 20% of patients reported adverse effects, most of which were mild to moderate.

The authors concluded that those who had previously used cannabis reported greater improvement than those who had never used cannabis.