Helen Thomson assesses research suggesting that cannabis was the only possible cause of death in a handful of cases:
Benno Hartung of University Hospital Düsseldorf in Germany and his colleagues conducted post-mortems on 15 people whose deaths were linked to cannabis use. To rule out other factors that might have contributed to death, such as alcohol use or liver disease, they performed numerous tests, including an autopsy, a toxicology exam, genetic tests and histological analysis of all organs. “It’s a diagnosis of exclusion so you have to rule out all other possibilities,” says Hartung.
Two of the deaths could not be attributed to anything but cannabis intoxication. Both were men who died of cardiac arrhythmia – when the heart beats too quickly or slowly. The team surmises that this was triggered by smoking cannabis. Both men had enough THC – an active chemical in cannabis – in their blood to suggest they had taken cannabis within hours of death. Neither had a history of cardiovascular problems or channelopathies – diseases that increase the risk of heart problems by affecting ion channels. “We did every test we could,” says Hartung.
But zoom out for a second. We’re talking two alleged deaths out of how many millions and millions of joints that have been passed around? Late last month, David Nutt, a former chief drug advisor to the UK, voiced skepticism about one pathologist’s ruling that cannabis was the cause of death for Gemma Moss:
I cannot begin to understand the pathologist’s certainty that cannabis killed Gemma Moss, but neither do I wish to contradict him outright. Taking any amount of cannabis, like all drugs, like so many activities, puts some stresses on the body. Cannabis usually makes the heart work a little harder and subtly affects its rate and rhythm. Any minor stress on the body can be the straw that breaks the camel’s back, the butterfly’s wingbeat that triggers the storm. Ms Moss had suffered with depression, which itself increases the risk of sudden cardiac death. It is quite plausible that the additional small stress caused by that cannabis joint triggered a one-in-a-million cardiac event, just as has been more frequently recorded from sport, sex, saunas and even straining on the toilet.
Exactly. The need to find some kind of terrible fate for the responsible pursuit of pleasure has been a Puritan fixture for aeons. In this particular case, they’ve come up completely empty.