Marijuana causes mental illness and violence

The evidence of ‘marijuana’s link to psychosis and violence is so strong, the issue so misunderstood, and the consequences so severe. It wrecks havoc in the brain, and all the evidence points that way.

The National Academy of Medicine still errs on the side of ‘we’re not sure’ after publishing a review of research on the health effects of marijuana. Marijuana ‘can be helpful’ in medicine but legalization is moving faster than science when it comes to marijuana.

The classic counter argument is that psychosis (a complex condition) is caused by other factors, and marijuana has offered relief for people with mental illness. But last year, a team of scientists in Montreal, Canada, found ‘it was cannabis use that predicted future violent behavior’ in patients at psychiatric hospitals.

The team spent a year tracking 1,136 men and women on psychiatric wards in three US cities (Missouri, Massachusetts, and Pittsburgh), interviewing them five times after they were discharged. The ones who had used marijuana were twice as likely to experience violent outbursts than those who hadn’t.

They concluded that the marijuana-violence connection was ‘uni-directional’.
Also last year, psychiatry professor Robin Murray of King’s College London presented a review of 10 other studies show a clear correlation between cannabis use and psychosis.

One of those studies found that the risk of psychosis went up as the potency of the cannabis increased. Most homicide rates (both at state level and national level) follow a fairly steady direction over the course of 10 years – some veering up, some down, with few erratic piques and troughs.

Washington’s murder rate is slightly different: it has snaked up and down quite consistently over the last 15 years, so it is a difficult measure to use in a short-term analysis of marijuana’s impact on society. But that hasn’t stopped people – both for and against legalization – from having a go.

The murder rate was up in 2008, down in 2010, up again sharply in 2012 (to the highest point in recent years), then down again in 2013 (though not as far as 2010), then up to another peak in 2015, then (only slightly) down again in 2016, before ticking back up.

The latest figures we have are from 2017, showing the murder rate had hit a new high, marginally exceeding 2012.
Marijuana was legalized for recreational use in 2012, and the drug became available to the public in July 2014, in the midst of a murder rate increase.

In 2016, pro-marijuana groups rejoiced at the murder rate dip, which many took to be a sign of marijuana’s relaxing effects taking hold state-wide. However, its dip was far shallower than in previous years, and not long after, it continued its trend up – this time to a new high.

That psychosis (when someone’s thought and emotions are disconnected from reality) is linked to homicide is a fact. The wealth of studies he presents should be evidence, he says, to convince the reader that cannabis is clearly linked to psychosis, and therefore to the murder rate.

The fact that we don’t all turn into murderers after smoking a joint doesn’t change that, he says, writing:
‘[A]lcohol can cause bar fights. It can cause drunken driving. It can cause domestic violence. It causes terrible violence.

There’s one kind of alcohol consumption that can just put [people] to sleep, and there’s another kind that can cause violence. With marijuana, those two things are also true, but we’ve sort of forgotten the second thing exists.
Doug Fields, a prominent neuroscientist who has studied marijuana’s effects on the brain, backs the statement.

The receptors in the brain [that cannabis stimulates], they are in the brain for a reason. They have a function,’ he explains. Messing with them is ‘like putting a monkey wrench in the system.’
That’s what all drugs do – opioids, cocaine, ketamine.

But Fields warns that many see marijuana as different because it’s from the ground; the idea is that something from the earth could only enhance what’s already going on in the brain. ‘The scientific evidence for cannabis having a [detrimental] effect, especially on the adolescent brain, is quite strong and well-replicated and diverse.

It is imperative to say: cannabis does not cure cancer. There is no evidence to prove that internet myth (for those looking for promising cancer treatments, read up instead on immunotherapy, the most encouraging new treatment in oncology). As for benefits, evidence supports four:
For those that like to feel high, THC (the psychoactive property in the marijuana plant) does make you feel high. The National Academy of Medicine says medical marijuana has been shown to ease pain and nausea for patients on chemotherapy – but that more trials are needed before they could properly endorse that. The National Academy of Medicine says that CBD (the non-psychoactive part of cannabis) has provided relief for some epilepsy patients, but scientists have struggled to replicate those findings widely so they stopped short of a thumbs up.

The drug may offer some relief for the growing number of people with anxiety, the Academy said, but more studies are needed. Beyond that, there isn’t sufficient research beyond anecdotal evidence.
US Surgeon General Jerome Adams has widespread support in his call for more research, not necessarily broader use of the drug.