Warning: Keep off the grass

by Jane Wheatley

Our correspondent hears testimony to the link between cannabis and psychosis

Judy Mylne woke with a start and glanced at her bedside clock; it was 3am. She went to the window and looked out over the quiet street of terraced houses: in the middle of the road her son James was Rollerblading, up and down, up and down, between the rows of parked cars. He must have woken her as he went out, she thought, leaning her forehead against the cool glass, watching him, feeling sick and afraid.

At first when James had started behaving oddly, being difficult, she’d put it down to normal teenage moodiness, probably exacerbated by his parents’ divorce when he was 16.  He’d always been very good at art, won prizes; you had to make allowances for artistic souls didn’t you? But now, two years later, it was a lot more worrying. He would rant at his mother obsessively about such things as the power of purple; friends avoided him, tutors on his art foundation course said they couldn’t teach him. “He’s a mess,” they told Judy.

One evening he dropped his Walkman on the floor, stamped on it and screamed: “I’m going to kill myself and take you with me.” He head-butted the wall, put his fist through a door and, with blood pouring from head and hand, ran out on to the street. The next day Judy took him to their GP, who referred him to a psychiatrist, to whom James admitted that he had been smoking cannabis regularly. By now he was hearing voices and thought people were following him. One night Judy came home from dinner to find James packing a few random objects into a bag inside a nest of twisted coat hangers. He said he was going to walk to Nepal in the morning.

“I thought: ‘My God, he’s really, really ill’,” Judy recalls. She closed the door quietly, fetched two sleeping pills, dissolved them in a glass of Coca-Cola and took it to him. Then she packed a bag and went to a friend’s house. In the morning she rang her GP, the psychiatrist, her older stepsons and her ex-husband. “I’m not going back to the house,” she told them, “you must go and get James and take him somewhere safe.”

James’s father, a barrister, was in court and asked leave to speak to the judge in his chambers. There he explained that his son had been taking drugs and was possibly psychotic. The judge looked at him: “My son has the same problem,” he said. “Go, and take as long as you need.” 

There but for fortune, it seems, go any of us with teenage children.

Though most people use cannabis without any obvious harm, most of us know of someone — our own child or a friend’s, a friend of a friend’s — who has got into trouble smoking weed, often skunk, which has higher levels of THC, the compound that gets you stoned.

The most extreme cases, such as James, develop a psychosis (schizophrenia or bipolar disorder) from which they may or may not recover. And it is no respecter of class, education or background. Dr Zerrin Atakan, a psychiatrist, sees severe cases at her clinic at London’s Maudsley Hospital: “Sadly many of these young people had been bright, sensitive, happy children,” she says. “Parents often feel dreadfully guilty for allowing them to smoke weed, because in their day, it was relatively harmless.”

Dr Atakan’s patients have usually been smoking from a young age, while the brain is still developing: “We know now that this is a significant risk factor in the development of psychosis. In an ideal world, no one would smoke before the age of 18.”

So, does cannabis cause psychosis? Almost certainly not by itself.

Cannabis-related psychosis is a relatively new feature in the landscape of mental illness and there is little reliable data on it. One study found that people who use cannabis before the age of 15 are at least four times more likely to develop schizophrenia, but all of them probably had a predisposition for psychosis in the first place — sometimes, though not always, indicated by a family history of mental health problems.

A new Australian review of current evidence found that 42 per cent of patients with psychosis had used cannabis. Yet, despite much greater use of skunk during the Nineties, there has been no significant increase in the incidence of psychosis in the past 30 years. Why not? David Kavanagh, of the University of Queensland, is one of the authors of the review:  

 “While cannabis may not cause psychosis, there is no doubt that it will trigger psychosis much earlier in vulnerable young people. This is very important because the period of late adolescence is critical for the completion of education and the development of social, emotional and sexual competence and a psychotic episode during this period is extremely disrupting.

“We also know that cannabis use tends to worsen subsequent symptoms and triggers further episodes.” British researchers believe that, because cannabis use by children is a recent phenomenon, the effects have yet to show in the figures and that there will be an increase in schizophrenia in this current decade. In one study of 2,500 young people, the effect of cannabis use was much stronger in those with a predisposition for psychosis (23.8 per cent) than in those without (5.6 per cent). But even when there is no known family history of mental illness, some children may be genetically more vulnerable than their peers, or have a personality that does not handle cannabis very well, and the Government has ordered a review of the evidence for this. There are genetic tests, but they are expensive and unlikely to be ordered until the damage is done. So how do you tell?

“Well, it’s not written on the forehead,” says Dr Atakan, wryly. Marjorie Wallace, founder of the mental health charity SANE, agrees that you cannot know who is vulnerable: “It’s like watching children playing Russian roulette; one of them is going to be a victim.”

Wallace has worked with schizophrenic young people for 20 years: is there a classic type? “Well, yes,” she concedes, “usually male, often more inward-looking, artistic and sensitive. Often very promising but then he starts to drop out of college, loses friends and slides quietly into isolation. After one psychotic breakdown, there is treatment and partial recovery but then he’ll go back to cannabis, substituting it for his medication.” The key, says Dr Atakan, is early intervention: “There is a prodromal phase of psychotic illness that parents can look out for: a teenager might be a bit more withdrawn, excitable, suspicious, touchy, anxious; he might develop an extreme interest or obsession with one thing, ignoring everything else and avoiding social contact. untreated psychosis — is critical, yet people are baffled and don’t know how to ask for help.”   Like many parents, Judy Mylne did not relate her son’s behaviour to drugs. “I think I was in denial,” she says now. By the time the family rescue squad was called in, he was in full-blown psychosis. He spent a month in the secure Nightingale Clinic, where he was put on a heavy dose of the antipsychotic drug Risperdal and underwent group therapy. He came home and, under the watchful eye of his mother, gradually reduced his dosage. He came off medication entirely in the summer of 2004. This year he completed his art degree, embarked on an MA and is successfully selling his art work.
James was lucky: he had a mother who stuck by him and, when the crisis
hit, there was money to pay for instant professional help. After the medical insurance ran out, there was high-quality psychiatric support at his local Hammersmith Hospital. But services across the rest of the country are patchy, to say the least. How can parents and teenagers get the help that they need?   Eddie Greenwood is the clinical services director of the mental health charity Rethink; he says that, because governments have been so slow to recognise the causal link between cannabis and psychosis, there is a dearth of provision for young sufferers: “Primary care diagnostic services are often poor. A GP may refer a young person to a community mental health team, but they are unlikely to have a case worker experienced in dual diagnosis — that is, a combination of psychosis and substance abuse.”
The Government is now urging NHS trusts to develop early intervention teams for young people with first-onset psychosis. “But the demand wildly outstrips supply,” says Greenwood, “and the problem is going to get worse before it gets better. ”

“This is the time to seek help. What we call D.U.P. — duration of

Last Christmas, says Judy, she asked him if he would come and help her to get the tree. “He asked me if I’d had a tree when he was in the clinic and who was at home for Christmas Day. I told him, just me and his sister. ‘Oh, Mum,’ he said, ‘I’m so sorry!’” Judy felt like punching the air. “I thought: ‘Yes! Insight, empathy, at last.’ And humour has returned, too. For four years, I hadn’t heard him laugh.”

At the moment, a young person presenting with psychotic symptoms is likely to be sent by his GP for assessment and then referred to a psychiatrist who may prescribe antipsychotic drugs and send him home. For families in rural and under-resourced areas, this could be disastrous. “If you leave these people with arm’s-length treatment, they will just deteriorate,” cautions Greenwood. “The key is active engagement: getting an intervention programme organised around the young person’s needs.”

Dr Atakan agrees: “Where these specialist services exist, they are resourced to supply psychological support as well as medical. Treatment is a contentious issue; it is not ethical to prescribe antipsychotics to young people who may not be psychotic. It’s a complex area.” And cannabis may be a useful scapegoat for families not wanting to face the stigma of mental illness. David Kavanagh: “When a young person develops a psychotic disorder, family members naturally search for reasons. The young person may be blamed for bringing it on himself by smoking. Not only may this not be true, but such hostile criticsm increases the likelihood of further episodes.” Last month, after pressure from police and some drugs charities, the Advisory Council on the Misuse of Drugs considered reclassifying cannabis as a Class B drug. But they are expected to recommend no change on the grounds that there is not enough new evidence to link it with mental illness. The council was also asked to consider giving a higher classification for skunk — “a more potent form of cannabis” — but this is thought to be unworkable. Dr Atakan would rather see cannabis legalised: “The present system is so bad; at least if it were legalised, some control mechanisms could be applied. At the moment it is in the hands of the dealers and it is in their interest to sell strong skunk. It needs to be regulated, like cigarettes, but most importantly there should be a thorough education campaign starting in primary school.”

Marjorie Wallace is dubious. “Until we know more about these new forms of cannabis, with their high THC levels and their effect on the young brain, we should not be giving out the message that this is a soft drug.”

                                                   *     *     *     *     *

“Sometimes I felt that people were talking about what I was thinking about”.  From the age of 14, I was smoking cannabis at weekends; by 18, I was smoking almost every night and doing some chemicals and pills at the weekends (LSD, ketamine, MDMA and cocaine). But, in comparison to others, I wasn’t doing many Class A drugs; I believe it was the consistent and accelerated use of cannabis that led to my diagnosis of drug-induced psychosis in 2000.   Out of about 25 drug users I knew then, three people, including myself, were creative, sensitive individuals — and not as bright as everyone else. I believe we were particularly vulnerable to the effects of cannabis. One of them, my best friend, jumped off a multistorey car park two years ago. The main difference between him and me was that I stopped taking drugs in 2001 and he didn’t. The thing about having something wrong with your mental state is that you can never escape it. When you can’t help yourself, you get angry, frustrated and sad about yourself. I would fleetingly remember my old self, when everything was fine and I was having so much fun — until it hurt too much. I wanted to be that person again. I believed that people were talking about me in public — and what was worse, what they were saying seemed to feed into the tangled web of delusional beliefs that  I had about my life. Sometimes I felt that people were talking about what I was thinking about. As a result, I thought I was some special character in a world that everyone knew of.

Paranoia is fundamentally egotistic and every conspiracy theory serves in some way to aggrandise the believer. My research into Buddhism has shone light on this and given me hope and help. I have recently been told by a doctor that my case is a great success. Certainly I feel one hundred times better than I did four years ago.


A search on Cannabis Psychosis produced 444 references. Here are the first 10.

1:  Ferdinand RF, van der Ende J, Bongers I, Selten JP, Huizink A, Verhulst FC. Related Articles, Links  Cannabis-psychosis pathway independent of other types of psychopathology. Schizophr Res. 2005 Nov 15;79(2-3):289-95. Epub 2005 Aug 25. PMID: 16125368 [PubMed – in process]

2:  Verdoux H, Tournier M, Cougnard A. Related Articles, Links  Impact of substance use on the onset and course of early psychosis. Schizophr Res. 2005 Nov 1;79(1):69-75. Epub 2005 Jan 11. PMID: 16198239 [PubMed – in process]

3:  Broome MR, Woolley JB, Tabraham P, Johns LC, Bramon E, Murray GK, Pariante C, McGuire PK, Murray RM. Related Articles, Links  What causes the onset of psychosis? Schizophr Res. 2005 Nov 1;79(1):23-34. PMID: 16198238 [PubMed – in process]

4:  Green B, Young R, Kavanagh D. Related Articles, Links  Cannabis use and misuse prevalence among people with psychosis. Br J Psychiatry. 2005 Oct;187:306-13.PMID: 16199787 [PubMed – in process]

5:  Viveros MP, Llorente R, Moreno E, Marco EM. Related Articles, Links  Behavioural and neuroendocrine effects of cannabinoids in critical developmental periods.Behav Pharmacol. 2005 Sep;16(5-6):353-62.  PMID: 16148439 [PubMed – in process]

6:  Long LE, Malone DT, Taylor DA. Related Articles, Links  Cannabidiol Reverses MK-801-Induced Disruption of Prepulse Inhibition in Mice.Neuropsychopharmacology. 2005 Jul 27; [Epub ahead of print] PMID: 16052245 [PubMed – as supplied by publisher]

7:  Clough AR, d’Abbs P, Cairney S, Gray D, Maruff P, Parker R, O’Reilly B. Related Articles, Links  Adverse mental health effects of cannabis use in two indigenous communities in Arnhem Land, Northern Territory, Australia: exploratory study.Aust N Z J Psychiatry. 2005 Jul;39(7):612-20.
PMID: 15996143 [PubMed – in process]

8:  Henquet C, Murray R, Linszen D, van Os J. Related Articles, Links  The environment and schizophrenia: the role of cannabis use.  Schizophr Bull. 2005 Jul;31(3):608-12. Epub 2005 Jun 23. PMID: 15976013 [PubMed – in process]

9:  Maki P, Veijola J, Jones PB, Murray GK, Koponen H, Tienari P, Miettunen J, Tanskanen P, Wahlberg KE, Koskinen J, Lauronen E, Isohanni M.

Related Articles,

 Predictors of schizophrenia–a review.

Br Med Bull. 2005 Jun 9;73:1-15. Print 2005.

PMID: 15947217 [PubMed – in process]

10:  van Os J, Henquet C, Stefanis N. Related Articles, Links  Cannabis-related psychosis and the gene-environment interaction: comments on Ferdinand et Al. 2005.  Addiction. 2005 Jun;100(6):874-5. No abstract available. PMID: 15918820 [PubMed – indexed for MEDLINE]


Where to get help:





The Maudsley Hospital provides a programme for people wishing to cut down their cannabis intake.

Further reading: Marijuana and Madness, edited by David Castle and Robin Murray. Cambridge University Press.

 Source:  The Times November 14, 2005

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