A study linking medical marijuana to an increase in recreational use has been criticised for failing to take into account the additional benefits of medical marijuana laws, such as a reduction in the use of opioids.
The research published in JAMA psychiatry found cannabis use and abuse or dependence in adults increased between 1991-92 and 2012-13 to a significantly greater extent in US states with medical marijuana laws compared to those states without.
The increased use may reflect factors such as easier access, increased potency, perceived safety or acceptability and generally more permissive attitudes, the researchers said.
They concluded that while medical marijuana laws may benefit some patients, its availability might also have adverse public health consequences.
“A prudent interpretation of our results is that professionals and the public should be educated on risks of cannabis use and benefits of treatment, and prevention/ intervention services for cannabis disorders should be provided,” they wrote.
However alcohol and drug expert Dr Alex Wodak told the limbic the differences between the states in terms of cannabis use or disorders – of the order of 1% – were very small.
He said the findings were unlikely to have implications for Victoria – the first Australian state to legalise cannabis for medicinal use in patients such as children with severe, intractable epilepsy.
Dr Wodak, president of the Australian Drug Law Reform Foundation, said the US study failed to mention evidence of additional benefits from medical marijuana.