Medicinal pot Lucy Nicholson/Reuters

Does cannabis really have medicinal properties? As the trend to legalise medical marijuana continues, there is growing evidence that it does help relieve some conditions, leading to hopes that it may help curb the US opioid addiction epidemic.

In the US, 28 states plus Washington DC have legalised medical marijuana in some form. An analysis has shown that compared with other states, those regions spent less money on prescriptions through Medicaid – the healthcare programme for people on low incomes – for five conditions sometimes treated with cannabis between 2007 and 2014. These conditions were pain, depression, nausea, psychosis and seizures.

The study could not prove that medical marijuana was causing the difference in prescription medication use. But there was no difference found in prescriptions for conditions unlikely to be treated with cannabis, such as antibiotics for infections. “It’s consistent with patients switching to marijuana for the five conditions,” says author David Bradford of the University of Georgia, US.


At the federal level, cannabis in plant form is still classed as an illegal drug that has no medicinal properties. “I hope that this will help encourage the Attorney General to change its status,” says Bradford.

Opioid epidemic

Bradford’s team used their figures to calculate that if all states had allowed use of medical marijuana in 2014, the total Medicaid savings that year would in theory have been about $1 billion. However, this pushes costs on to patients, points out Bradford. Even in states where medical marijuana is legal, it is not covered by health insurance. “It isn’t all roses because the patients are picking up the full tab.”

The US is seeing record numbers of deaths from prescription painkillers and illegal opioids such as heroin. Some people become addicted to opioids when they start using prescription painkillers such as oxycodone for a health problem, and later end up switching to illegally obtained prescription medications or heroin.

Beau Kilmer of the think tank RAND Drug Policy Research Center says the latest findings are consistent with most previous research. Some studies have also found correlations between the availability of medical marijuana and fewer opioid overdose deaths.

Journal reference: Health Affairs, DOI: 10.1377/hithaff.2016.1135