An Australian study of 1,500 people revealed no strong findings supporting the use of cannabis in the treatment of chronic non-cancer pain.

The study published in the journal Lancet Public Health found those using cannabis had greater pain and anxiety, were coping less, and reported that pain was interfering more in their life.

There has been speculation that using cannabis for pain may allow people to reduce their prescribed opioid use but research has been limited until now. The latest study shows there is unlikely to be a single effective treatment.



A long term study by the University of New South Wales, one of the world’s longest in-depth community studies on pharmaceutical opioids and non-cancer pain, found little to support using cannabis to treat chronic pain.

The four-year study of more than 1,500 Australians prescribed opioids for non-cancer pain suggest that there is a need for caution in using medicinal cannabis.

Those in the study who used cannabis, and there were many among those with chronic non-cancer pain who had been prescribed opioids, actually had greater pain, anxiety and were coping less.

The study was conducted before the legislation of cannabis in Australia for medicinal use. The users in the study would have most likely smoked the cannabis and not used drops or other means.

The use of cannabis for medicinal purposes has been increasing worldwide. And there has been speculation that using cannabis for pain may also allow people to reduce their prescribed opioid use but research has been limited until now.

In Australia, medicinal cannabis was legalized in February 2016 and the New South Wales Government has developed the Medicinal Cannabis Compassionate Use Scheme for adults with a terminal illness.

The New South Wales Government has also established the Centre for Medicinal Cannabis Research and Innovation, with $12 million in funding over four years, to help further understanding of cannabis and cannabis medicines for therapeutic purposes.

“Chronic non-cancer pain is a complex problem," says Dr Gabrielle Campbell at the University of New South Wales , the lead author in the latest study.

"For most people, there is unlikely to be a single effective treatment.

"In our study of people living with chronic non-cancer pain who were prescribed pharmaceutical opioids, despite reporting perceived benefits from cannabis use, we found no strong evidence that cannabis use reduced participants’ pain or opioid use over time."

The Pain and Opioids IN Treatment (POINT) study, published today in the journal Lancet Public Health, looked at the effect of cannabis on pain, on the extent to which this interfered with everyday life, and on prescribed opioid use.

In the study, participants were recruited through community pharmacies and completed comprehensive assessments of their pain, physical and mental health, medication and cannabis.

Participants had been in pain for a median of 10 years and taken prescribed opioids for for four years. There were very high rates of physical and mental health problems.

At each assessment, participants who were using cannabis reported greater pain and anxiety, were coping less well with their pain, and reported that pain was interfering more in their life, compared to those not using cannabis.

There was no clear evidence that cannabis led to reduced pain severity or pain interference or led participants to reduce their opioid use or dose.

However, the users thought otherwise. Those who used cannabis, despite the study finding no evidence, reported that cannabis was effective (mean score of 7 out of 10).

One possibility is that cannabis improves sleep, which in turn improves well-being, say the researchers.

The researchers say double-blind randomized placebo-controlled clinical trials are needed to better understand the impact of cannabis.