Can Cannabis Cure Schizophrenia?

By Richard Shrubb, Freelance sailing, health and social affairs journalist

ould cannabis treat or even cure schizophrenia? Things look promising according to research taking place at the moment. There is  a  long way to go however, possibly as long as 15 years

until you can have your psychiatrist prescribe you Cannabidiol (CBD) for psychosis.

Professor Val Curran is a leading psychiatrist who is based at Imperial College London. She says “there  are  around 70 unique chemicals that you can only get from cannabis plants. CBD is just one of many being researched.”

Pharmaceutical companies will pick a chemical up and try to develop it into a medicine. GW Pharmaceuticals is a major player where extracts of cannabis are concerned, having developed a spray for Multiple Sclerosis called Sativex. Mark Rogerson, their Communications Director, explains that CBD has been suspected of having antipsy- chotic properties for quite some time. He says, “when GW began developing cannabis as medicine we thought  THC to be more like a racing car engine and CBD more like the brakes. THC sends you up very quickly while CBD holds you back. It has been only recently that we started to see that CBD has more therapeutic properties beyond.”

Published in March, the study published in the Journal of Translational Psychiatry compared CBD with a modern

antipsychotic called Amisulpiride. Two exciting findings came out of it. Firstly that CBD has far fewer side effects than modern antipsychotics. The report suggested: “Either treatment was safe and led to significant clinical improvement, but cannabidiol displayed a markedly supe- rior side-effect profile.”

Prof Curran explains that with CBD “there is no weight gain or side effects associated with antipsychotics used today.”

Ben Sessa is a Somerset psychiatrist with a passion for get- ting psychedelics tested for medical purposes. He explains that the side effects of current antipsychotics can be off putting to people taking medication. “These side effects can include uncontrollable muscle twitches and weight gain. They can be very worrying for the patient, and often puts them off taking them.”

Things look promising but there are a lot of hurdles in the way of CBD being prescribed by psychiatrists. The first is, would a pharmaceutical industry cur- rently making £billions from controlling schizophrenia want a cure?

The newer antipsychotics make almost half those who take them obese, and there is an elevated risk of diabetes. To date science hasn’t been able to blame on the drugs themselves, but the rates of the disease are far higher in those who take antipsychotics than those who do not. For psychiatric patients and clinicians alike, having a “superior side effect profile” suggests that taking medication would be far less of a problem. For the doctor, their patient will have a higher chance of taking their medica- tion and avert the risk of further breakdowns. For the patient the physical side effects aren’t so off putting, and reduces the risk of a section posse coming to take them away.

The next part of the study suggested that: “inhibition of anandamide deactivation may contribute to the antipsy- chotic effects of cannabidiol potentially representing a completely new mechanism in the treatment of schizo- phrenia.”

Prof Curran explains this. “The paper backs up previous work, that psychosis can be controlled in a way that has- n’t been considered in medicine. Anandamide is found in cerebrospinal fluid – the stuff that comes out when you get a lumbar puncture in hospital. By keeping levels of anan- damide high in this fluid, so psychotic symptoms are reduced”. Scientists being humorous creatures, “Ananda”  is Sanskrit for “bliss” – anandamide can also be described as the “bliss chemical”!

Research into drug efficacy typically requires it to be tried on a large number of people. It also has to be repeatable

– another researcher has to do exactly the same study and get similar results. This study at the University of Cologne involved 42 patients. By the time full scale clinical trials take place well over 1000 people will take  CBD in any one trial, to give you an idea as to how small this study was.

Beginner’s luck is where your friend who has never played golf before hits a Hole in One on his first round  with you. It doesn’t mean he will be trouncing Tiger Woods at the Open – just that he is lucky! The same applies in science. The more a study is repeated with similar results, the stronger the findings are. Often you get pure flukes – your friend on the golf course may find in all future rounds he gets a pasting by everyone he plays with.  The CBD study is going to be repeated soon at Yale University in the USA. If the findings are reproducible, then this research may be considered validated, and not pure fluke.

Prof Curran says that something even more exciting may come from research into CBD – schizophrenia may be stopped altogether in some cases. “Some research shows that high anandamide levels in patients with early stage psychosis will delay or even prevent the onset of schizo- phrenia in some cases.” Prof Curran continues, “the later you develop schizophrenia in life the better your chances for recovery.” Preventing schizophrenia would be  the most exciting news in psychiatry in decades.

Dr Sagnik Bhattacharyya is a psychiatrist working  at King’s College London, who is planning  a study  on this.  No research has taken place yet, but will start in the next few months.  Dr Bhattacharyya  says,  “the study  is going to be small and is essentially to see if it is worth going down this road. If the results show something, then others can fund a larger scale project.”

He goes on to explain the questions that will be asked before going on to a clinical trial: ”if it prevents emerging psychotic symptoms or reduces their severity to a greater extent than the placebo group then this will be interesting to science as a whole.”

As a psychiatrist Dr Bhattacharyya comes across a lot of patients in the early stages of psychosis, around 1/3rd of who will develop a full blown psychotic disorder like schizophrenia. He says “our problem is we just don’t  know who will or won’t get schizophrenia among these people. We can offer them antipsychotics, or offer Cognitive Behavioural Therapy at the minute,  which works but they aren’t very effective alone. A combination of CBT and antipsychotics are often the best course to take.”

Psychiatrists and patients worry about the side effects. Dr Bhattacharyya goes on, “weight gain can be a big issue.” Essentially if you are going to get schizophrenia then at present, no one can prevent it. Side effects deter psychia- trists from offering drugs unnecessarily and patients can end up refusing them.

Offering a side effect free drug to patients to dampen their psychosis would be an answer – if they develop schizo- phrenia, their symptoms would be being treated from the start, and many may be prevented from developing the ill- ness at all.

Things look promising but there are a lot of hurdles in the way of CBD being prescribed by psychiatrists. The first is, would a pharmaceutical industry currently making £bil- lions from controlling schizophrenia want a cure? Brad Burge, Communications Director of the Multidisciplinary Association of Psychedelic Studies in California doesn’t think so. He suggests, “Big Pharma isn’t financially moti- vated to find cures for mental illness. A cure for an illness isn’t profitable–the real payoff for them is in long-term treatments.”

The cost involved in pharmaceutical research – many tens of millions of £ – may simply not be returned in, for exam- ple, giving someone a 6 week course of treatment to pre- vent their illness.

A spokesperson for the UK Medicines and Healthcare Regulatory Authority explains how pharmaceutical com- panies make their money back. He says, “ it involves data exclusivity for 10 years – no other company can use the research undertaken by the company to get a license for  a similar drug.” This prevents companies making generic drugs. Famously all sorts of people have tried  making fake Viagra but this isn’t licensed, and hasn’t  been through the very stringent clinical trial process. If it is of similar chemical makeup it could be very dangerous as Pfizer, Viagra’s makers, don’t have to disclose all the pit- falls of what one ingredient or another can have on some- one taking it.

The MHRA wouldn’t say whether there is a CBD based antipsychotic in the pipeline citing commercial confiden- tiality. Mark Rogerson suggests that GW Pharmaceuticals aren’t developing CBD as an antipsychotic. “At  the moment we’re looking at cancer pain, epilepsy and dia- betes drugs using cannabinoids, but we aren’t developing anything for psychosis.”

The next issue is licensing. We have looked at the concept of cohorts above. People are all individuals in the  way they react to a drug. The more people who take a dose for

a period of time the more individual reactions can be measured. Prof Curran suggests that “the safety profile of CBD looks fantastic at the moment – it is an extraordinary chemical”.

Staying on safety some readers will find the next bit nasty (as I do reporting it). Animal testing suggests that in mon- keys the Lethal Dose 50 measurement (that is, the dose of a drug at which half the monkeys will die) of CBD is 212 grammes of CBD per kilo of animal – in theory you have  to consume a quarter of your bodyweight of CBD (in my case, 25 kilos!) before you have a fifty fifty chance of being poisoned by it.

Will the Daily Mail one day rave that “CANNABIS  CURES SCHIZOPHRENIA”? Not in the short  term. 

There are a lot of hoops to jump through before it is even on the radar. Typically it takes 15 years for a drug to go from small scale testing to the pharmacy shelves. As some- one who takes antipsychotics every day myself, I will be at the front of the queue if it happens, but the question is “if” rather than “when”.

CBD study can be found online herewww.nature.com/tp/journal/v2/n3/full/tp201215a.htm