The Woolcock Institute of Medical Research

Update August 2022: We're looking for volunteers to take part in exciting new research studies on cannabis-related medications, including the CAN-Rest and CUPID studies. See a list of all studies.

Sydney scientists are trialling a cannabis-based medicine to get insomniacs snoozing soundly again.

The Woolcock Institute of Medical Research is enlisting people with chronic insomnia to test out a new drug thought to promote a deep, restful sleep in those who consistently struggle to get enough. The study, in partnership with the Lambert Initiative for Cannabinoid Therapeutics, is the first to use high-density EEG to investigate how cannabis affects the brain during sleep in people with chronic insomnia.

“Anecdotally we know cannabis, in its plant form, acts as a sleep aid, but there are virtually no studies showing the effectiveness of a pharmaceutical-grade formulation,” says study leader and Woolcock insomnia specialist Professor Ron Grunstein. “This study will show us whether the drug improves sleep and, importantly, if those who take it feel brighter and more alert the next day.”

“If successful, we have a natural alternative to sleeping tablets for the tens of thousands of Australians who suffer from this debilitating condition.”

Studies estimate about 10 per cent of the adult population have insomnia, defined as a lack of quality sleep that impairs daytime functioning across all spheres of life, including work, learning, social and personal.

“To date, the most successful pharmacological treatment includes hypnotics such as benzodiazepines that typically work well, but a new discovery may work even better or have a better side effect profile than standard medication,” Professor Grunstein explains.

The research team is investigating the effects of the Cannabis sativa plant, which consists of more than 100 different phytocannabinoids, the most common being delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). “THC is the phytocannabinoid associated with cannabis intoxication but is also known to have some sedating properties and therapeutic effects in relation to pain, muscle spasms and other conditions,” says Professor Iain McGregor, academic director of the Lambert Initiative for Cannabinoid Therapeutics. “CBD, on the other hand, does not intoxicate, but also has an increasingly well-described range of therapeutic actions including anti-anxiety properties.”

The trial medication contains THC and CBD in a 1:20 ratio, and administered orally at a dose that is unlikely to cause significant intoxication. The researchers are enlisting 20 adults aged 35 to 60 with diagnosed chronic insomnia to trial both the drug and a placebo over two different nights in a central Sydney sleep lab. 

“On each occasion, we’ll measure their sleep as well as their next day cognition and driving performance,” Professor Grunstein says. “It’s our hope that the trial drug significantly improves sleep quality and quantity for these patients compared with the placebo, and that the medication doesn’t impede brain function the day after.”

Participants will complete a sleep diary and wear a wrist-worn Actiwatch to assess daily activity and sleep/wake cycle. “They’ll also undergo a high-density EEG sleep study to measure the brain’s response during sleep and while awake,” Professor Grunstein says. “We’re very excited to be using this technology as an outcome measure for the first time in a cannabis-based medicine insomnia study.”