According to new research recently published in JAMA Network Open, more people with depression are self-medicating with cannabis, which evidence suggests is unlikely to be beneficial to say the least.

US researchers have just published their analysis of data from the ongoing National Health and Nutrition Examination Survey (NHANES), comparing the prevalence of depression and cannabis use in 2005/6 with 2015/16 among 16,000 American adults (aged 20 to 59) taken from a cross-section of the population.

Over the decade in question, it appears the percentage of adults who reported having used cannabis in the previous month increased by almost 50% (from 12.2% to 17.3%).

And although the prevalence of depression did not change over this time period, the study found that, with time, people with depression were increasingly likely to not only report having used cannabis in the last month, they were more than 200% more likely to be using cannabis on a daily or almost daily basis.

So while the prevalence of cannabis use in the general population was found to be 17.3% in 2016, among people with depression it was approximately 30%. And if you consider daily or almost daily use, the study shows this was the pattern of use for just over 6% of the general cohort at the end of the study compared with 15% if you just look at people with depression.

Of course this is a US study, so the increasing prevalence of cannabis use over the past two decades has to be viewed in the context of increased availability and more permissive laws across the majority of American states. And you have to take into account US advertising. Cannabis is frequently marketed as a remedy for mood disorders and there has been a widespread decrease in the public’s perception of risks associated with cannabis use despite existing evidence that cannabis can worsen depressive symptoms.

And that’s where the real concern lies. People with depression might be using cannabis in the mistaken belief it could be beneficial whereas the exact opposite is more likely.

“Individuals with depression who use cannabis may represent a high-risk group for cannabis-involved adverse consequences, potential worsening of symptoms, and suicidality,” the study authors said.

Interestingly the study findings do not suggest that cannabis use causes depression. Despite the quite significant jump in the percentage of people using the drug the prevalence of depression remained the same.

Nonetheless, the higher proportion of depressed people using cannabis represents an opportunity for intervention that might improve psychological outcomes, the researchers suggest.

“In health care settings where depression is addressed, discussion with patients regarding the frequency of their cannabis use, strategies for cutting back and the effects of cannabis on depressive symptoms may be useful,” they concluded.

Ref: JAMA Network Open.2020;3(8):e2013802. doi:10.1001/jamanetworkopen.2020.13802