A new study in the Yale Journal of Biology and Medicine has revealed that smoking cannabis provides significant and fast-acting relief from depression, and that this effect is predominantly due to THC[i]. Crucially, the authors say that their study is not based on the weak marijuana strains that are typically licensed for research purposes, but uses real-life data recorded from nearly 2,000 cannabis users around the world.
According to the researchers, many cannabis studies provide unreliable findings as they are conducted using government-approved marijuana products that often don’t resemble the types of cultivars used by regular people. To get around this stumbling block, the authors of this latest study used data collected by a smartphone app called the Releaf App, which allows users to record information about their experiences with medical cannabis.
Analysing data from 1,819 people who completed a total of 5,876 self-administered sessions, the researchers found that 95.8 percent of users experienced substantial relief from depression within moments of smoking. On average, the intensity of depressive symptoms fell by 3.76 points on a scale from zero to ten, although this varied depending on the type of bud used.
Interestingly, no notable differences were seen between Indica, Sativa and hybrid strains, although THC levels were found to have a huge impact on the anti-depressant effect of a given plant. More specifically, those with more than ten percent THC reliably produced the greatest relief from depression, yet this benefit appears to plateau once a certain concentration is reached.
While cannabis products containing between ten and 19 percent THC generated significantly greater relief than those containing under ten percent, no extra benefit was seen when this was increased to between 20 and 35 percent.
This study is far from the first to reveal the fast-acting anti-depressant effects of cannabis. A previous paper in the Journal of Affective Disorders found that just two puffs of weed is enough to produce a noticeable reduction in depressive symptoms, and that maximum relief is reached after ten puffs[ii].
In that study, higher THC levels were also linked to the greatest reductions in feelings of stress, while CBD was strongly associated with a decrease in depression.
Taken together, these two studies would seem to imply that numerous compounds found in cannabis can help with depression and other forms of emotional distress, and it seems likely that the interactions between these ingredients – otherwise known as the entourage effect – plays a huge role. For example, numerous terpenes present in marijuana have also shown potential as anti-depressants, suggesting that these may support and enhance the effects of certain cannabinoids.
Among these is D-limonene, which is found in cannabis but also comprises more than 50 percent of commercial citrus oils. Research has revealed that these oils significantly reduce the need for anti-depressants in people with clinical depression, causing some scientists to speculate that D-limonene may also contribute to the soothing effect of marijuana[iii].
At present, the most commonly used anti-depressant pharmaceuticals are selective serotonin uptake inhibitors (SSRIs) and monoamine oxidase inhibitors (MOIs), both of which typically take weeks before they start to produce any noticeable benefits. On top of that, these drugs are often associated with negative side effects like sedation and suicidal ideation.
The fact that cannabis works much faster than these conventional medications and does not produce such undesirable side effects could therefore be something of a game-changer if it becomes approved as a treatment for depression.
[i] Li X, Diviant JP, Stith SS, Brockelman F, Keeling K, Hall B, Vigil JM. Focus: Plant-based Medicine and Pharmacology: The Effectiveness of Cannabis Flower for Immediate Relief from Symptoms of Depression. The Yale journal of biology and medicine. 2020 Jun;93(2):251. – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7309674/
[ii] Cuttler C, Spradlin A, McLaughlin RJ. A naturalistic examination of the perceived effects of cannabis on negative affect. Journal of affective disorders. 2018 Aug 1;235:198-205. – https://pubmed.ncbi.nlm.nih.gov/29656267/
[iii] Komori T, Fujiwara R, Tanida M, Nomura J, Yokoyama MM. Effects of citrus fragrance on immune function and depressive states. Neuroimmunomodulation. 1995;2(3):174-80. – https://www.karger.com/Article/Abstract/96889