Study examines risk of CUDs among medical cannabis patients

A new paper highlights the need for greater public health messaging around the risks of cannabis use disorders among those prescribed it for medicinal purposes. 

While cannabis can have a wide range of potential therapeutic benefits, like any drug or medication it can have adverse effects too.

Those who consume cannabis on a regular basis may be at an increased risk of developing cannabis use disorders (CUDs), which is defined in the DSM-5 as a ‘problematic pattern of cannabis (marijuana) use leading to clinically significant impairment or distress.

CUDs are generally associated with recreational consumption, with estimates suggesting that they could impact around 22% of consumers and 13 million people globally.

To date there has been little research on the rates of CUDs among patients who are prescribed cannabis medicinally, although studies have suggested that they could still be at risk.

Researchers at the University of Queensland in Australia have conducted the first systematic review and meta-analysis of existing studies, to estimate the prevalence and symptoms of CUDs in medical cannabis patients.

What the study found 

In total, the research team reviewed 14 publications, which provided data on the prevalence of CUDs in 3,681 participants from five different countries. 

The review demonstrated that demographic factors, mental health disorders and the management of chronic pain with medicinal cannabis were associated with an increased risk of developing CUDs.

After conducting meta-analyses on the data and including all periods using the DSM-5 criteria the prevalence of CUDs in people who use medicinal cannabis was estimated to be around 25%. 

The findings suggest that the risk of CUDs ‘may be higher in people who use medicinal cannabis frequently, use greater quantities of medicinal cannabis daily and are more likely to use medicinal cannabis via inhalation’.

The authors state: “The prevalence of CUDs in people who use medicinal cannabis is substantial and comparable to people who use cannabis for recreational reasons, emphasising the need for ongoing research to monitor the prevalence of CUDs in people who use medicinal cannabis.”

They also highlight the need for public health messaging on the adverse effects of using cannabis for medicinal reasons, “irrespective of whether it is self-prescribed or authorised by a medical professional”.

Complexities in cannabis use motives 

There are a number of limitations to the study, including the “dual use motives of cannabis” (medical and recreational) which “complicate the estimation of the prevalence of CUDs” in medicinal cannabis patients.

The paper highlights the challenges in distinguishing medicinal patients from recreational consumers given there is often overlap between the two and the complexities these presents for cannabis research.

“There is a serious question here of how researchers, clinicians and public health agencies are to distinguish medicinal cannabis patients when varied proportions also use cannabis recreationally whilst authorised for medicinal use and others claim to be using cannabis medicinally without authorisation,” they write.

“The current review highlights the complexity in delineating recreational and medicinal cannabis consumers and emphasises both the need for a valid methodology to separate use motives, or the consistent use of reliable tools in research to monitor motives of cannabis use when prescribed medicinally.”