A team of researchers from the University of Western Australia is set to embark on a world-first human clinical trial specifically examining the effects of medicinal cannabis on subjects suffering from chronic insomnia. The trial will be led by the university's Center for Sleep Science and run in conjunction with Australian medical research and development company Zelda Therapeutics.

Trial participants will be administered medicinal cannabinoid oil under the tongue one hour before going to bed, every night for two weeks. A placebo group will be also administered an inactive oil for two weeks before the groups switch to take the opposite preparation. The study will be blind, meaning each group will not know whether they are receiving the active or placebo medication.

Sleep quality will be measured via wrist-based sleep trackers and questionnaires, with the trial also incorporating three monitored overnight sessions in the university's sleep center.

"Prescription medicines such as benzodiazepines (e.g. Temazepam), non-benzodiazepine hypnotics (e.g.Stilnox, Sonata, Imovane) and some antidepressants and antihistamines can have unpleasant side effects and when used long-term can result in dependence and withdrawal symptoms," says lead on the upcoming study, Peter Eastwood. "Based on previous research we believe a small dose of medicinal cannabinoid may be effective for treating chronic insomnia and have fewer side effects than current drug treatment options."

The relationship between cannabis and sleep is a surprisingly understudied area. There are over 100 different chemicals present in the cannabis plant and recent medical research has only just begun to isolate these different compounds and understand their individual effects. The most abundant and well-known compounds research tends to focus on are THC (D9-tetrahydrocannabinol), CBD (cannabidiol) and CBN (cannabinol).

THC is the big psychoactive player in cannabis, responsible for its infamous "high", while CBD is the compound often responsible for many of the plant's positive medical uses. It is only recently that researchers have begun to parse the different effects of THC and CBD on sleep cycles, with CBD in particular having been found to have a mildly stimulating effect in low-doses, but effective sleep-inducing effects in higher doses.

It is unclear exactly what kind of cannabinoid preparation will be used in this upcoming study, but Zelda Therapeutics does specifically discuss CBN as a compound of interest in relation to treating insomnia. CBN, a product of degradation or oxidation of THC, is one of the most sedating compounds found in cannabis. One research lab suggests a small dose of CBN can result in a similar level of sedation as diazepam, and in combination with THC could produce an effective sleep aid.

The results from the upcoming trial will hopefully be available within the next 12 months, adding much needed new clinical data to help us understand the effects of these cannabis compounds on sleep and insomnia.