In a world-first, University of Western Australia researchers will test if the sedating effect of medicinal cannabis works on the one-in-three Australians who regularly have difficulty falling or staying asleep, reports Perth Now.

Lead researcher Peter Eastwood said insomnia cost the nation more than $66 billion a year, including lost productivity and health problems.

Current treatments for insomnia include cognitive behavioural therapy, which is “very effective” but time consuming and expensive, and the psychiatric drugs benzodiazepine, which are addictive and come with numerous side effects, Professor Eastwood told AAP on Monday.

“It’s a huge market,” he said.

Medicinal cannabis has previously been tested for its effectiveness in controlling epilepsy and chronic pain.