Credit: Raul Arboldeda/AFP / Getty


November 15, 2019   5 mins

Eddie used to be an IT professional living a comfortable middle-class life, before he was admitted to our ward — initially under Section 2 of the Mental Health Act for assessment and later to Section 3 for treatment.

Eddie — not his real name — was 35 and not known to mental health services, a relatively unusual situation as symptoms normally develop earlier, often in late adolescence. University-educated and highly-skilled, he was living a comfortable life working in the IT sector. Then, five years before I saw him, he had landed a prestigious new job in Amsterdam.

It was difficult to piece together what had happened to him, because his thought process had become completely disordered, but we eventually learned that Eddie had begun smoking cannabis while in Amsterdam; at first only occasionally, and then more regularly until eventually he was using it every day.

Over a period of time, as psychotic symptoms first emerged and then developed into something bigger, Eddie began his downward drift, losing his job and eventually becoming homeless. His distraught mother paid for him to come back to Britain to live with her, before he was admitted to hospital.

There was no history of serious mental illness in the family, nor had Eddie exhibited any notable problems in childhood or even as he got older; things only began to fall apart in his life after he moved to Amsterdam, where high-strength cannabis is freely available.

Eventually Eddie received a diagnosis of schizophrenia and was placed on a community treatment order, instituted primarily to ensure that he complied with the anti-psychotic medication, given fortnightly via intra-muscular injection and prescribed in order to control his symptoms. Any hopes that he and his mother might have had for his life were now greatly diminished — job, career, children, family, all of his and her dreams crushed. Eddie was by now living with what is essentially a disability, with the prospect of a reduced life expectancy and quality of life.

I’ve been a registered mental health nurse since 2007. Post-qualification I initially worked in a ward for six years, followed by another six in the community. The gap between public perceptions of psychiatry and what you actually see working on the wards and outside can be pretty big sometimes, but none more so when it comes to the issue of cannabis.

I first became aware of the drug as a teen, well before I had even thought about what I was going to do as a career. Like a lot of people my age — I’m 39 now — I knew people who smoked cannabis, and it wasn’t considered a big deal at the time. Despite being illegal, it was widely seen as a harmless soft drug to experiment with, sort of a rite-of-passage to adulthood. This was in the late 1990s, when most cannabis on the black market was low in THC, the psychoactive compound that delivers the high and makes the drug enjoyable to smoke.

My next encounter with cannabis was very different, involving witnessing people on the psychiatric wards where I worked from 2007-2013. Prior to becoming a mental health nurse I had known many people who had smoked cannabis but who had never experienced psychotic symptoms. In my new job it was rare to meet anyone experiencing psychotic symptoms who was not also a marijuana smoker.

The type of cannabis being smoked was by this time very different from that of the late 1990s. Commonly known as “skunk” (after its very pungent smell), this new form had come to dominate the market.

Skunk is much higher in THC than its predecessors, but almost all forms of the drug have become stronger. In a recently published polemic on the dangers of legalisation, Tell Your Children: The Truth About Marijuana, Mental Illness and Violence, author and New York Times regular Alex Berenson wrote that: “through the mid-1970s, most marijuana consumed in the United States contained less than 2 percent THC. Today’s users wouldn’t even recognise that drug as marijuana. Marijuana sold at legal dispensaries now routinely contains 25 percent THC.”

This closely mirrors the situation in Britain, where the reputation that cannabis has acquired in the public consciousness — a mild, harmless, benign, relaxing intoxicant — is dangerously out-of-date.

A recent study published by the Lancet gave a stark warning, stating boldly that “daily cannabis use was associated with increased odds of psychotic disorder compared with never users … increasing to nearly five-times increased odds for daily use of high-potency types of cannabis”. The evidence for a link between cannabis use and serious mental illness is clear, but the difficulty remains in conveying this information to the public.

Psychosis is the clinical term describing what most lay people would understand — and what we historically would have referred to — as “madness”. There is still, even today, a large degree of stigma attached to these symptoms, and consequently not many people wish to speak about their experiences of them. You are unlikely to even hear about them unless you work in mental health services; and unless you have experienced psychosis yourself, or know someone who has, it is difficult to grasp the devastation that it causes to people’s lives.

With psychotic symptoms experienced by cannabis smokers we are primarily talking about hallucinations (usually auditory) and delusions (usually persecutory i.e paranoid.) They can be extremely frightening to those who experience them and, as a consequence, can often lead to social withdrawal, as well as social drift.

The social drift hypothesis notes that individuals who suffer from serious mental illness (SMI) — in particular those diagnosed with schizophrenia — are more likely than the general population to live in socioeconomically deprived areas and that the clinical features of mental illness contribute towards this downward trajectory in socio-economic class.

During my time working as a staff nurse on an acute inpatient male psychiatric unit I observed social drift first-hand, Eddie being only one such example. But social drift and social withdrawal also make it even less likely that the average person will know someone who has experienced these symptoms, and so their story goes untold.

It is true that not everyone who smokes cannabis will experience these symptoms. It is often asserted that the link between cannabis and psychosis is merely correlational and not in any way causative, an argument intended to muddy the waters, when THC is known as a risk factor in mental illness. It is an argument never made in relation to cigarette smoking and lung cancer, even though most cigarette smokers do not die of lung cancer, either.

But cannabis is not safe: it is associated with a number of serious side effects, including problems related to pregnancy — see here, here , here and here — life-threatening vomiting, changes to neuroanatomy, a significantly increased risk of youth suicide — see here, here and also here — an increased number of hospitalisations — see here and here — increased postoperative pain, impaired cognition/lowered IQ in adolescents and an increased risk of car crash injuries — see here, here, here and also here.

It is, therefore, incumbent upon mental health professionals to speak up so that the general public are made aware of the risks. This has become even more important now that North America has undergone a wave of cannabis legalisation spreading from Colorado to Canada, emboldening advocates in Britain in the process.

It is true, as Berenson argues, that decriminalisation reduces the civil rights concerns expressed by legalisation advocates and campaigners. One could argue that cannabis has already been de facto decriminalised in this country anyway, despite the rather overblown claims that are sometimes made to the contrary, and de jure decriminalisation therefore seems the logical next step.

Yet legalisation tacitly endorses and normalises the idea that the drug is safe, which it isn’t, and risks creating an entrenched business community who will then promote cannabis as a product; it will do this without providing us with any certainty or assurances that the process will reduce the black market for the drug or reduce its potency.

This is what has happened in North America already, and represents the worst of all possible worlds – and once we legalise the drug it will be very difficult to turn the clock back.

If cannabis is legalised then the only winners will be big tobacco, alcohol and pharma. The rest of us will all be losers, and the worst affected will be those already living at the margins of society.


Peter Hurst is a psychiatric nurse and political blogger based in Liverpool.

@post_liberal