The modern medical community embraces cannabis’ therapeutic potential. Many researchers are especially interested in cannabis’ effect on mood disorders because these conditions are notoriously difficult to treat.
There’s ample proof that cannabinoids like tetrahydrocannabinol (THC) and cannabidiol (CBD) can decrease anxiety.  Studies also show that terpenes, the dominant constituents of aromatic oils found in plants, can influence your mood. However, relatively little research has examined the “entourage effect,” or what happens when cannabinoids and terpenes are combined.
In 2019, a team from Israel’s Bar-Ilan University concluded that: “Further research is warranted to investigate the potential therapeutic value of adding terpenes to treatment with CBD, with or without additional THC for the benefit of patients suffering from depression, anxiety or BD [bipolar disorder]”  The team noted that the “value of such entourage effects” might increase cannabis’ efficacy as a treatment option for psychiatric disorders.
For instance, more than 40 million Americans currently suffer from anxiety. Numerous studies have shown that both THC and CBD can work as anxiolytic agents. [2,3] While some studies have demonstrated anti-depressive attributes of CBD in rats, no clinical trial has evaluated the cannabinoid’s efficacy against depression in humans. Available research on cannabinoids and BD have proven conflicting.
Research indicates that terpenes may treat anxiety as well. For instance, one trial gave adults diagnosed with anxiety either a dose of lavender oil, an antidepressant, or a placebo.  Subjects who took the lavender experienced the greatest reduction in symptoms over ten weeks.
Lavender contains linalool, a terpenoid that’s also present in many cannabis cultivars. If the entourage effect applies to cannabis, linalool-rich cultivars might be particularly useful for anxiety patients. Lavender and hyssop essentials oils also have demonstrated promise for treating depression.  Another study showed the power of a citrus scent against depression, which proved to be better than antidepressants. 
Dr. Ethan Russo, in his hallmark “Taming THC” paper, reported that limonene, pinene, and linalool could provide mood-enhancing benefits to dementia and Alzheimer’s patients.  Russo also cites multiple studies that demonstrate the involvement of our endocannabinoid systems in mediating depression, anxiety, and post-traumatic stress disorder.
So, there are promising studies that highlight the therapeutic effects of cannabinoids and terpenes for anxious, depressed, and bipolar patients. However, until more research is conducted, we won’t know precisely how or if the entourage effect contributes to cannabis’ beneficial effect on mood disorders.
References: Ferber SG, Namdar D, Hen-Shoval D, et al. The “entourage effect”: Terpenes coupled with cannabinoids for the treatment of mood disorders and anxiety disorders. Curr Neuropharmacol. 2020;18(2):87-96. [journal impact factor = 7.363; times cited = 40]
 Lisboa SF, Gomes FV, Terzian AL, et al. The endocannabinoid system and anxiety. Vitam Horm. 2017;103:193-279. [journal impact factor = 2.557; times cited = 27]
 Rubino T, Realini N, Castiglioni C, et al. Role in anxiety behavior of the endocannabinoid system in the prefrontal cortex. Cereb Cortex. 2008;18(6):1292-1301. [journal impact factor = 5.043; times cited = 250]
 Kasper S, Gastpar M, Müller WE, et al. Lavender oil preparation Silexan is effective in generalized anxiety disorder–a randomized, double-blind comparison to placebo and paroxetine. Int J Neuropsychopharmacol. 2014;17(6):859-869. [journal impact factor = 4.333; times cited = 129]
 Guzmán-Gutiérrez SL, Bonilla-Jaime H, Gómez-Cansino R, Reyes-Chilpa R. Linalool and β-pinene exert their antidepressant-like activity through the monoaminergic pathway. Life Sci. 2015;128:24-29. [journal impact factor = 5.037; times cited = 92]
 Komori T, Fujiwara R, Tanida M, Nomura J, Yokoyama MM. Effects of citrus fragrance on immune function and depressive states. Neuroimmunomodulation. 1995;2(3):174-180. [journal impact factor = 2.492; times cited = 179]
 Russo EB. Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects. Br J Pharmacol. 2011;163(7):1344-1364. [journal impact factor = 8.739; times cited = 899]
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