News: Placebo – controlled study. Medicinal cannabis for chronic sleep disorders

chronic sleep disorder - Medizinalcannabis bei chronischen Schlafstörungen

Everyone has experience with sleep disorders, for example due to stress. Chronic sleep disorders are extremely stressful. Sufferers cannot get enough rest at night which affects health and productivity. However many sleeping pills have side effects such as daytime sleepiness and carry a risk of addiction.

In a double-blind study an Australian research team investigated for the first time the effect of medicinal cannabis on chronic sleep disorders (chronic insomnia). The team came to the conclusion: A cannabis extract with the cannabinoids tetrahydrocannabinol (THC), cannabinol (CBN) and cannabidiol (CBD) is an effective and safe therapy for chronic insomnia.

At what point are sleep disorders chronic?

6 to 15 percent of the population has to struggle with chronic insomnia which manifests itself in the form of difficulty falling asleep and/or sleeping through the night.

Experts speak of chronic insomnia if the complaints occur on more than 3 nights a week and persist for longer than 3 months. Patients with insomnia need more than half an hour to fall asleep. Patients with sleep maintenance disorders wake up during the night and stay awake for more than 30 minutes or wake up very early in the morning (more than 30 minutes before the desired wake-up time).

Chronic sleep disorders are best treated with cognitive behavioural therapy. If the sleep problems persist or behavioural therapy cannot be done, sleeping pills (hypnotics) can be helpful. However these drugs often have side effects such as daytime sleepiness and impaired mental performance and motor skills – associated with a risk of falling.

In addition there is the development of tolerance and a risk of dependence and abuse. Many sleeping pills can also influence the sleep phases. For example people who take benzodiazepines dream less.

Two-week cross-over study with cannabis extract and placebo in 24 sufferers with chronic insomnia

The randomised, placebo-controlled cross-over study at the Centre for Sleep Research at the University of Western Australia involved 24 patients with an average age of 53 years.

Sleep behaviour without medication was monitored for 2 weeks with an activity monitor worn on the wrist and with sleep diaries.

The participants recorded the time it took to fall asleep, the duration of sleep, the quality of sleep and the restfulness of sleep. In addition the researchers carried out a polysomnography in the sleep laboratory whereby the body functions of the sleeping person are monitored during one night.

The 24 participants were then randomly assigned to the cannabinoid or placebo group and neither the patients nor the researchers knew whether they were taking placebo or cannabis. The two-week study phase was followed by a week without medication before the patients switched to the other group. Monitoring was also done by means of a sleep diary, activity tracker and polysomnography.

The researchers used an oily extract with THC, CBN, CBD and terpenes as the cannabis-based drug. The placebo extract contained the same terpenes, but no cannabinoids. The participants took the drugs sublingually, i.e. under the tongue one hour before going to bed every day. After four days the participants could double the dose after consulting a doctor. The researchers contacted the participants during the first days and after increases in dose to determine possible side effects.

Side effects disappear overnight or quickly after awakening

Two-thirds (67%) reported mild side effects but these usually disappeared overnight or shortly after awakening. The most common were dry mouth and dizziness.

Only one person dropped out of the study due to adverse effects. In the end data from 23 patients were analysed. However caution should be exercised in older patients and those with a psychiatric history as hallucinations and dizziness are problematic.

Medicinal cannabis shortens the time it takes to fall asleep and extends sleep time

The sleep diaries of the study participants showed clear improvements in sleep: Sleep duration increased: When taking the placebo extract, sleep duration averaged 5.06 hours and climbed to 6.11 hours with medicinal cannabis. Cannabis was thus able to extend sleep duration by an hour. The time to fall asleep was also 38.1 minutes with cannabis, compared to 46.9 minutes with placebo. Those affected fell asleep 8.8 minutes faster on average with the cannabis drug.

The activity monitor and polysomnography measurements also showed improvements: According to the measuring devices, the sleep duration under placebo was 6.52 hours and increased by 33.5 minutes to 7.07 hours when taking the cannabis extract. Thus the participants who took cannabis reached the recommended sleep time of about 7 hours for adults.

Cannabis improves sleep quality and recovery

In addition the participants rated sleep quality and restfulness on a scale from 0 (very poor or not rested) to 4 (very good or very rested).

Without medication and under placebo the patients rated sleep quality at 2.5 and restfulness at 1.2. Both scores improved with cannabis extract to 1.8 for rest and 3.2 for sleep quality. So with medicinal cannabis, people slept better and woke up more refreshed. Another advantage is that the cannabis extract studied does not influence the duration of the sleep stages.

Larger studies necessary

In order to gain further information on the optimal time to take the drug, the scientific team examined the blood levels of THC, CBD and CBN in some of the participants.

The results show that depending on whether there are problems falling asleep or sleeping through the night, a different time of taking the drug could be useful: In the case of difficulties falling asleep, taking the drug as early as 2 to 4 hours before bedtime can be helpful. If there are difficulties sleeping through the night, it might be better to take it one hour before going to bed.

The researchers concluded that medicinal cannabis can be an option for chronic sleep disorders. However studies with larger groups of people are needed to clearly prove the effect and to determine the optimal dosage.


Jennifer H Walsh, Kathleen J Maddison, Tim Rankin, Kevin Murray, Nigel McArdle, Melissa J Ree, David R Hillman, Peter R Eastwood, Treating Insomnia Symptoms with Medicinal Cannabis: A Randomized, Cross-Over Trial of the Efficacy of a Cannabinoid Medicine Compared with Placebo, Sleep, 2021;, zsab149,

About Minyi

Minyi Lü leidet an chronischen Schmerzen aufgrund ihrer Fingerarthrose. Ihre Beschwerden behandelt sie seit 2017 sehr erfolgreich mit medizinischem Cannabis. Als PTA und Pharmaziestudentin bringt sie nun ihr Know-how ein, um über die neuesten wissenschaftlichen Erkenntnisse rund um Medizinalcannabis zu berichten.