Di Martin: On the 9th floor of St Vincent's Hospital in Sydney, a patient lies in bed watching a violent spring storm roll in.

Paul O'Grady is a former Labor politician, serving in the NSW Upper House for nearly a decade.

Paul O'Grady: Well, I had cancer about three years ago, anal cancer. I had 32 bouts of radiation, which was the most excruciating pain that I'd ever, ever, ever experienced. And they would give me morphine, which I absolutely loathed, because it was like having a little man inside your head, playing with your head.

Di Martin: Around this time Paul O'Grady received a package in the mail.

Paul O'Grady: And here were two little bottles of liquid marijuana, with instructions, one drop in the morning, et cetera, which I started taking, until they found it in my fridge. And then I just went back to having a bit of a joint.

Di Martin: This is Paul O'Grady's first interview about using medical cannabis. He says it dulls his pain, suppresses nausea and stimulates his appetite.

He has long had HIV, and says after his cancer treatment he continued to use cannabis.

Paul O'Grady: The HIV drugs I take cause nausea and total lack of appetite. And so most days I will just have a couple of puffs of a joint, so it's not about being stoned, it just helps you to think, okay, well, here's lunch, I'll get some of this down.

Di Martin: How important is that for your overall health at the moment?

Paul O'Grady: Well, it's crucial, because it's crucial to get food down, it's crucial to be walking and being active, it's crucial that you get food into you so that you can walk.

Di Martin: Welcome to Background Briefing.

It's estimated thousands of Australians are already using cannabis for medical reasons, risking criminal penalty to ease their suffering. This widespread civil disobedience has finally led Australian politics to its first tentative step towards legalisation.

The states and territories have just agreed on a national approach to cannabis trials, with NSW saying it will take the lead. Details of what is to be trialled, when, and where are due late this year.

But the move has been quickly criticised as unnecessary and expensive. The Victorian ALP, tipped to win next month's state election, says there's already enough science to move straight to legalising medical cannabis. Here's Opposition Leader Daniel Andrews:

Daniel Andrews: Look around the world, there is an enormous amount of literature, there is an enormous amount of peer-reviewed work, where there have been clinical trials in lots of other parts of the world. Now, I think there is an undeniable momentum to make this change because it's changing lives, it's saving lives, it's exactly the sort of law reform that we should be into.

Di Martin: Legislators in more than 20 US states, Canada, Israel and a number of European countries have already legalised cannabis for medical use, citing scores of clinical trials demonstrating its benefits.

David Caldicott: So the reasons that we don't use it are not scientific, they are political and legislative.

Di Martin: Dr David Caldicott runs the Emergency Department at Canberra's Calvary Hospital. He's one of the few senior Australian clinicians who say medical cannabis should be legalised, and that some of his patients are already using it.

David Caldicott: The people who admit it to me are largely the people who have a terminal diagnosis and who frankly don't really care who knows whether they are using it or not.

Di Martin: And what do they say?

David Caldicott: They say that they get some relief from it. They use it to supplement the medications that they're prescribed which don't seem to be working for them.

Di Martin: And what kinds of conditions are they trying to address with medical cannabis?

David Caldicott: Largely issues of pain, the intractable pain associated with terrible diagnoses, and occasionally for the anorexia that is associated with terminal illness. I think this is something that could be probably be prescribed as it was in the 19th century as a herbal supplement to minimise discomfort in a given population.

Di Martin: So the science is in on that?

David Caldicott: The science has been in on this for a long time.

David Caldicott: Dr Caldicott says cannabis should now be legal for the terminally ill and those with profound illnesses that don't respond to conventional medication. He wants to run a tightly controlled trial of current users and how they're using the plant. It's not only being smoked. There are also products like oils and tinctures being sold on the black market.

Advocates for the raw plant are on one side of a deep divide now opening up in the medical cannabis debate. On the other side is the Australian Medical Association, which wants a fully tested medicine.

Tony Bartone: We in no form or process looking at the crude plant and legalising the plant for medicinal purposes.

Di Martin: Dr Tony Bartone heads the AMA's Victorian branch, and agrees that cannabis does appear to have some medical benefit. But he says there are so many different types of cannabis plant, that benefit is not clear from one batch to the next. So Australia should only consider drugs approved at the Federal level by the Therapeutic Goods Administration, or TGA.

Tony Bartone: What we are seeking to do is exactly what any other new medicine would be required to do coming onto the market.

Di Martin: So you're only looking at legalised cannabis for medical purposes that is a medicine passed by the TGA?

Tony Bartone: Correct.

Di Martin: What about as a herbal supplement?

Tony Bartone: That is somewhere where we are not going at this stage.

Di Martin: Doesn't any one drug often take 10 years and tens of millions of dollars to bring to market?

Tony Bartone: We are many years already down the track on medicinal cannabis, so it's not going to take 10 years.

Di Martin: Dr Bartone could not say when such a drug may be available.

In Canberra, Dr David Caldicott says taking the pharmaceutical route is time consuming and expensive. Cannabis has hundreds of active ingredients.

David Caldicott: These are complex compounds, difficult to prepare, and that greatly increases the cost of any commercial product. So there is an argument by some people that we should just wait until the pharmaceutical companies take control of this, own it and sell it. But this will be at an enormous cost to the Australian taxpayer and to the poor individuals who need to consume these issues. This is a plant that can be grown. This can be grown like a tomato at roughly the same price.

Di Martin: David Caldicott specialises in illicit drugs and toxicology and he says the side effects of cannabis are benign compared to many of the medicines he now prescribes. He says special cannabis strains for specific medical conditions have been developed overseas, and are available to import or to grow from seed. He also says patients can tolerate small variations in plant chemistry.

But the AMA says there is no hard science behind those different plant strains, just anecdotal evidence. The AMA says there should only be trials of cannabis-based pharmaceutical drugs already on the market. There are two different types, which are not now available in Australia. We'll hear more detail about that a bit later, including objections to that course of action.

Dr Tony Bartone says Australia must proceed cautiously.

Tony Bartone: The safety of our patients is our primary concern. The facts are not clear at this stage, and we need to be sure that we are doing no harm.

Di Martin: Dr Bartone says in the meantime even the terminally ill should stay away from cannabis.

Tony Bartone: And I can understand the frustration and the lack of empowerment some patients would feel in this situation. But that is no reason to then abandon all sense and throw caution to the wind.

Meg McGowan: Yeah, that is advice from someone not facing terminal illness.

Di Martin: Legalisation is getting support from some unexpected quarters. This is former NSW Detective Superintendent Meg McGowan.

Meg McGowan: I think pragmatically if you are facing terminal illness, you will do anything to try and stay alive. And the people that I'm aware of who are taking it are taking it because they see it as their last hope, or they are taking it for palliative care because the alternatives for them are so horrendous in terms of side-effects.

Di Martin: Meg McGowan is also giving her first interview about medical cannabis. As a police officer she played a primary role in keeping a lid on cannabis in NSW.

Meg McGowan: I was a detective superintendent. I had been involved in putting together drug policy and drug law enforcement.

Di Martin: Personally your attitude to cannabis at that time?

Meg McGowan: Personally my attitude to cannabis at that time was that it was a dangerous illegal drug and that nobody should be anywhere near it.

Di Martin: Meg McGowan says it's now time for the lid to come off cannabis, for medical reasons.

Meg McGowan: I have now completely shifted my opinion based on my own research. I believe cannabis should be available for medical use.

Di Martin: So when did your attitude to cannabis start to shift?

Meg McGowan: I was diagnosed last year with triple negative breast cancer. Given my background as a detective I immediately hit the internet and started having a look at what causes it and what treats it.

Di Martin: Triple negative breast cancer is rare, aggressive and doesn't respond to conventional hormone therapy. So Meg McGowan researched what the cancer might respond to, and discovered that she's interested in cannabis not to ease her death but to try and prevent it.

Meg McGowan: And one of the things that turned up was that there had been trials using cannabis that had killed triple negative breast cancer cells both in vitro and in vivo. So in a test tube and in animals, the cancer that I have responded to cannabis. So I am hopeful that we will see legalisation and as a consequence of legalisation we will start to see some of the research that needs to be done to determine what it's best used for.

Di Martin: Are you using cannabis oils or products for your cancer?

Meg McGowan: No, because at the moment I'm cancer free. The mastectomy successfully removed all of my breast tissue. Certainly if I have recurrence of cancer that would be something that I would be prepared to do, because my personal view is that might save my life.

Di Martin: Meg McGowan's claim is not as fanciful as it may first appear once you consider the science. A leading cannabis researcher says the results of early experiments on the anti-tumour properties of the plant are simply remarkable. Sydney University's Dr David Allsop has conducted trials on both the harms and benefits of cannabis. He explains there are more than a hundred molecules in the cannabis plant called cannabinoids.

David Allsop: We're talking about research that has happened in cells, people culturing cancer cells and then applying cannabinoids to them, different cannabinoids—THC, cannabidiol—and seeing how the cells respond. And that research is staggering. It really is amazing. Cannabinoids absolutely kill cancer cells, they stop them from communicating with each other, they stop them from proliferating, they are known to be able to restrict the blood vessels that supply cancer cells with their nutrients and energy. This has been shown for almost all types of cancer.

Di Martin: Dr Allsop makes clear this in no way proves that cannabis cures cancer, and as a rule only a small percentage of laboratory research is confirmed in animal and human trials. But he says successful animal trials have been carried out for some cancers. Dr Allsop explains there's been one human trial, a Spanish study of nine people with terminal brain cancer. The results were inconclusive. While tumour growth was slowed in eight people, all died within the year. You can find a link to that study on our website.

David Allsop says anti-tumour trials started a long time ago, but have been significantly hampered.

David Allsop: They have been happening for a decade or more. Certainly more. People have been very interested in this area for a long time. But of course cannabinoids are illegal. And that means that people, the engines of change in society like pharmaceutical companies and industry, the people who if they can smell a dollar they will generate change, are reluctant.

Di Martin: In Australia, cannabis sits in the highest level of prohibition—a Schedule 9—along with heroin. Drugs in this category are said to have no medical application, and it's very hard for scientists to get access.

David Allsop: If it is a Schedule 9, well, it becomes extremely difficult to justify in a grant application the feasibility of doing this work. You have to then jump through all sorts of regulatory hoops that take years and years to get the medicine on your table and ready to deliver to a patient.

Di Martin: Dr Allsop was funded recently to study one of the few pharmaceutical products containing cannabis extract. He found it a deeply frustrating process.

David Allsop: We were funded to do a 12-month trial, and it took us one year just to get the regulatory approval. And then running the study took another year and a half.

Di Martin: Which had to be paid for…

David Allsop: Which had to be paid for from the generosity of my collaborators who had to find the money to support me and the study from their own meagre funds.

Di Martin: Is it your conclusion that efforts to try and study the benefits of cannabis are just stymied before they begin?

David Allsop: Absolutely, yes, yes.

Di Martin: Leaving ordinary people to take science into their own hands and carry out their own experiments.

It didn't take Background Briefing long to find several people who are using cannabis to treat cancer, including a 20-year-old university student from Melbourne, who we'll call Edward. It's not his real name. Edward's been diagnosed with synovial sarcoma, a rare soft tissue cancer that started in his ankle. He's been through bruising rounds of chemotherapy, radiation and surgery.

Edward: And two weeks after the surgery they did a biopsy and scans and came back and said it has metastasised and spread, and there also may have been two masses in my lower torso, and they weren't going to biopsy it, because they said, look, at this point we think your disease is incurable and there is not a heap we can do.

Di Martin: After another four rounds of chemo, Edward started taking one ml of cannabis oil daily for six months. This is his father John:

John: And on 25 August this year, 2014, he had a full body PET scan where they inject him with a glucose, for want of a better word, and the cancer cells take up the glucose. We got the result saying that the PET scan was clear.

Di Martin: No tumours?

John: No tumours. So the findings are there are no abnormality in the right groin or pelvis to indicate progressive nodal metastatic disease, and the distant metastases, none.

Di Martin: That's John reading from his son's PET scan results.

At their ordinary suburban home in Melbourne's south-east, Edward's mum pulls out a bread and butter plate. She wants to be known as Marie. On the plate is an open Cryovac-ed plastic pouch.

Marie: This is the stuff that came in from overseas. So I heat this up each night

Di Martin: Just describe what this is?

Marie: This is the cannabis oil. So it's quite a thick substance, as you can see it's sort of tar-like.

Di Martin: It's like red curry paste.

Marie: It doesn't taste like that! So each night I just heat a little bit of this up and put it onto the spoon and my son then takes it from there.

Di Martin: And then just drink it?

Edward: It depends on its consistency but usually it's so thick and sticky that I roll it into a ball almost and take it like a tablet.

Di Martin: Marie says using cannabis was a last resort, considered only after Edward ran out of medical options. She vividly remembers the day the oncologist delivered that news.

Marie: 'We can't do anything else for you.' That's what we were told. So you have to, you've got no choices, you've got to start looking for something alternative or give in.

Di Martin: So how did you actually even go about accessing a supply of cannabis oil?

Edward: My friend helped me, and he helped set up this meeting, this late night somewhere in some car park by the beach, and we had to go buy them out of the back of someone's car at night-time and spend a lot of money doing it.

Di Martin: Edward's father explains they were guided by a treatment plan sourced off the internet. This is John:

John: It's recommended for cancer patients when they get onto the oil that you should try and consume 60 mls or 60 grams in 60 days. So we went out and purchased a pound of marijuana, which was several thousands of dollars, we ended up, after the extraction process, we ended up with about 45 mls of oil. And as the supplies were drying up we started getting it in from overseas.

Di Martin: John's son has experienced a range of side effects from the cannabis oil. There's mood swings, and some problems concentrating. Edward's also had a frightening episode after stopping his oil regime, and then restarting it a week later.

Edward: I woke up at three o'clock in the morning and straight away I could tell something was not right. I was just all over my head, seeing things, thoughts, like threefold and very powerful. And I can remember I was in Mum's room, I don't even know, I was talking about God and religion and war and screaming 'I'm enlightened' and all of this really crazy stuff. So it's the unfortunate nature of what we have had to go through.

Di Martin: Edward then pulls out a photo of himself taken after his last rounds of palliative chemo.

Edward: When people question me about the side-effects of cannabis use and what it does I just show them the picture that I have saved on my phone of when I was very, very ill in hospital having chemotherapy.

Di Martin: Can you show us?

Edward: Sure…

Di Martin: Look at the colour of your skin!

Edward: I know. I prefer the side effects of cannabis oil to that.

Di Martin: This family don't know exactly what the cannabis oil is doing, and are not sure if Edward's cancer is cured or in remission. They have seen people in online forums die despite their self-medication. But Edward says there are also success stories, and for him, cannabis use gives some hope.

Edward: I don't like to jump on board things unless I can see evidence and stuff. But I see people all across the world through the community and they are posting pictures of their scans and they are completely clear and all they are doing is taking medical cannabis. I'm hoping, I really am hoping that it is fighting and actively combating the cancer and destroying it and clearing my system out. So that's what I can really hope for.

Di Martin: This family's story has had quite an impact on Victorian ALP Opposition leader Daniel Andrews.

Daniel Andrews: Something has worked there. I don't know what. I'm not a doctor, I'm not an oncologist. But again, this is one case amongst so many that I think is adding to the momentum that says we've got to do better, have a better framework, have a legal framework where we get to the bottom of some of these mysteries, well above and beyond the proven benefits.

Di Martin: Daniel Andrews will go to next month's state election on a platform to legalise some forms of medical cannabis now being used by Victorian families, products like oils and tinctures. But he doesn't want to legalise the crude plant. Daniel Andrews says that risks blurring the line between recreational use and medical use.

Daniel Andrews: No one is smoking anything. This can sometimes be mischaracterised or misinterpreted as in some way legalising marijuana in a broader sense, of course that's not what this is about. This is about saving lives, it's not about wrecking lives, it's not about illicit drug use at all.

Di Martin: And he says it's not just a drug to relieve symptoms. Here, unprompted, Daniel Andrews raises the possibility of cannabis as a cure.

Daniel Andrews: We need to clear that up, we need to have a much more solid footing, play our part in developing an evidence base for future products, for other ways, for other conditions where this medical cannabis in all of its different forms might save lives and be curative in the future.

Di Martin: At Sydney University, leading cannabis researcher David Allsop says it's high time Australia investigates the benefits of this plant. He reveals Sydney University wants funding to establish a National Cannabis Research Centre. Dr Allsop says there's great interest in cannabis to treat a range of conditions, including obesity, PTSD and even Alzheimer's.

David Allsop: We are scrambling over ourselves in science to try to work out what the uses are for all of these new compounds that we are finding that seem to be really interesting medically for a whole range of different things. Cannabis has many, many other molecules than THC, the one that gets you high, that are all non-psychoactive. That means they don't affect your cognition or your memory in any negative way.

Di Martin: David Allsop says most objections to cannabis focus on its harms. He's an authority on cannabis dependence. He says its harms should not be underestimated, but need to be put in perspective.

David Allsop: Cannabis can precipitate psychosis. But it's important to point out that it only occurs, as far as we know, in those people who are already predisposed to it. So it's definitely not as black and white as 'cannabis causes psychosis'.

Di Martin: Any other major harms?

David Allsop: Respiratory harms. Same as with cigarettes in a sense, it's smoking. But you can do things about that. You can work out different methods of ingesting the cannabis that don't cause those harms. The other major harm is the risk of developing dependence on cannabis, and dependence comes with spending a lot of your time seeking it out and spending a lot of money on it. But those risks are fairly infrequent when you consider the scale of cannabis use.

Di Martin: Dr Allsop says most of the research on harms is from observational studies of recreational users, people smoking street cannabis which is very high in THC, the only known cannabinoid that's psychoactive. He says medical cannabis strains developed overseas wouldn't have the same side effects.

Cannabis harms were certainly a focus of a pivotal NSW Upper House inquiry last year. Nationals MLC Trevor Khan was part of that inquiry, which heard a range of objections to legalisation.

Trevor Khan: The Department of Health had an extraordinarily negative attitude towards medicinal cannabis. We were being told that it causes sterility and infertility, impotence. We got the full range of exercises. And we said, well look, if you are terminally ill are issues of long-term use a problem if you have got six months to live and what you're trying to do is to re-establish a degree of capacity to eat? And the answer was no.

Di Martin: Trevor Khan recently met with other committee members including its Chair, Nationals Sarah Mitchell, and the Greens John Kaye.

John Kaye: I think it is fair to say that what happened was that Sarah's committee was a kind of turning point in the body of politics. It was a unanimous finding of Nationals, Liberals, Greens, Shooters Party and Labor that we should do something in this space.

Di Martin: That 'something' was to recommend cannabis be decriminalised for terminally ill adults, registering them with the Health Department so they couldn't be arrested. But the NSW government said no.

It was then the Haslam family from rural NSW got involved, with such a compelling story that the debate completely turned around. 24-year-old Dan Haslam has stage four bowel cancer. He uses cannabis both to quell the nausea of chemotherapy, and with the hope he may stall the spread of his cancer. His father was an undercover cop in the drug squad, and his mother Lucy, a former nurse.

Lucy Haslam: We've soul-searched over this. This has been something that we've always taught our kids; it's not great to be involved with recreational drug use. But in this context for Dan it is entirely the right thing to do.

Di Martin: Lucy Haslam speaking on ABC New England. After the government refused to decriminalise, she sought out MLC Trevor Khan to see what more could be done politically.

Trevor Khan: We said, look, the prospect of doing anything before the next election is just about nil. And she said, 'So we do nothing?' And either Sarah or I said something like, well look, you can go out there and try and create some energy in the community, that can force politicians to do something. Neither Sarah nor I had any belief that you would end up with a Change.org petition with over 200,000 people having signed it and all the rest of the things that have been done. They created an energy which is quite extraordinary.

Di Martin: At the same time these Upper House backbenchers started drafting a bill to decriminalise for terminally ill adults. The bill was well advanced, and the backbenchers were quietly confident it would pass parliament this month. Until the Premier Mike Baird gazumped them. Speaking in parliament, here Mike Baird might sound like he's all for legalisation:

Mike Baird: The country has waited too long, this state has waited too long, it's time we got this done.

Di Martin: But if you listen closely to what 'this' is, it has little to do with changing the law.

Mike Baird: The New South Wales government is announcing a clinical trial for medical cannabis that will be established to explore further the role that cannabis can play in providing relief for patients suffering from a range of debilitating or terminal illnesses.

Di Martin: Clinical trials can take years to complete and participant numbers are often limited. At the earliest, trials won't begin until later next year, after the next NSW election. The announcement destroyed the backbenchers' bill.

In St Vincent's Hospital, former Labor MLC Paul O'Grady says many of his former colleagues are afraid to move forward on this issue.

Paul O'Grady: The parliament will get up in about November, it won't sit again until after the election in March, so I don't really see this as going anywhere, and whether he is re-elected or not, who knows.

Di Martin: What do you think is going on politically? What have you learned?

Paul O'Grady: That it has been used to slow something down. I think politicians are more conservative than the electorate on these sorts of issues. I think they are fearful of stepping outside the box.

Di Martin: The NSW government did add a caveat to their announcement; there will be new police guidelines so officers don't have to charge the terminally ill who use cannabis. But again, little detail is known. The police force told Background Briefing they are internal documents and won't be released.

Former Detective Superintendent Meg McGowan says police don't want to legalise medical cannabis because they say recreational use will increase. She says that concern is baseless.

Meg McGowan: Anybody who wishes to use cannabis recreationally is already doing so. It's so widely available.

Di Martin: Meg McGowan has written to her former boss urging a change in law. Here she reveals that in his reply, NSW Police Commissioner Andrew Scipione has promised to raise the issue with his commanders.

Meg McGowan: And I'll just read a little bit of it: 'You raise a number of compelling arguments that deserve careful and genuine consideration. I will raise your arguments with the relevant commands and ensure that they are seriously considered.'

Di Martin: The current debate has been firmly focused on legalising for the terminally ill, not for those with chronic conditions. And in NSW, not for children. Yet suppliers of black market cannabis products told Background Briefing they are providing oils or tinctures to more than 160 sick kids. At least two of those families have been visited by government agencies and warned not to speak to the media.

So this NSW family asked us not to use their names. They are not yet using cannabis for their seriously ill six-year-old, but intend to if laws don't change. Here the parents appeal for their child to be included in coming trials.

Father: Reconsider the cohort of people they are targeting here because it's more than the terminally ill. It is cases like our son, and I'm sure there's a lot of other cases just like that.

Mother: You know, the next seizure could be the one that kills him, or damages him permanently.

Father: Better reconsider.

Di Martin: Their six year old son has Dravet syndrome, a profound form of epilepsy.

Mother: He has tonic-clonic seizures.

Di Martin: What does that mean?

Mother: That means that his whole body is consumed with the seizure, he keels over into a fit. They are frying his brain essentially every time they happen and it's important to have them under control.

Di Martin: This couple understands that cannabis can impact on the developing brain. But the father says his son's current medications all have significant side effects of their own.

Father: There's enough side-effects between his three drugs that he takes each day to fill an A3 page. He has got the shaky movements, he has major problems with sleeping, he is very, very unsteady on his feet. And he still doesn't have seizure control.

Di Martin: This couple say they've now exhausted every medicine legally available to treat their son's epilepsy. They want cannabis legalised now, and they want medical guidance on how to use it.

Mother: We're not chemists, we don't know what to measure, we don't know how to administer it, and we don't know how much is enough, how much is too much. It needs to be monitored by a professional who can recognise warning signs.

Di Martin: These are cautious people, who could lose their jobs for giving their son cannabis, which is a risk they say they are willing to take if they can't access trials, or if their son's medications stop working.

Father: If things suddenly declined like they appear to be going for us, then certainly we won't be thinking of waiting.

Mother: We would be trolling the streets or however you obtain it to try and do the best for our son. We have to put his health first.

Di Martin: You're listening to Background Briefing, and a program on the polarised positions on how and when to legalise medical cannabis. I'm Di Martin.

An interesting and wholly unexpected entry to this debate came recently from Prime Minister Tony Abbot. His support for medical cannabis was first revealed by 2GB radio host Alan Jones, who's been lobbying him to legalise cannabis for the terminally ill.

Alan Jones: Mr Abbot replied to me, and the date of the letter is the 23rd of August, in part saying: 'Alan, I have no problem with the medical use of cannabis, just as I have no problem with the medical use of opiates. I was under the impression that personal use of cannabis was no longer an offence in NSW.' Mr Abbot said: 'I agree that the regulation of medicines is a thicket of complexity, bureaucracy and corporate and institutional self-interest. My basic contention is that something that has been found to be safe in a reliable jurisdiction shouldn't need to be tested again here.'

Di Martin: Advocates for legalisation say those comments prove it's time to change the law. But the Australian Medical Association disagrees. It says recently announced national clinical trials won't repeat what's happening overseas. Here's Dr Tony Bartone from the AMA's Victorian branch:

Tony Bartone: No, we are not replicating. Where there is reliable and consistent and robust information already available, that does not need to be required.

Di Martin: By those high standards, there are very few cannabis clinical trials that would make the grade. Certainly not those conducted on the raw plant. The AMA says even the many trials on pharmaceutical cannabis products are not yet enough.

There are broadly two types of cannabis derived medicines now available overseas. There are drugs that contain laboratory-made THC. The generic names are dronabinol and nabilone. They started to come on the market in the 1970s.

The second type has only recently been released. It's a plant extract, containing equal parts of THC and another key molecule, CBD. It's called Sativex. Dr Tony Bartone says Sativex has been approved by the Therapeutic Goods Administration, the Federal body that approves medicines.

Tony Bartone: There is one TGA approved cannabinoid product on the market at the moment, Sativex. It can be administered on a case-by-case basis as part of a trial.

Di Martin: But it would only be trials of pharmaceutical products like Sativex?

Tony Bartone: Absolutely. On that point we can be absolutely clear, that it will be only be chemically consistent and composition determined products, it will not be the crude plant.

Di Martin: The TGA has only approved Sativex to treat spasticity in multiple sclerosis. So Dr Bartone says those trials would not need to be repeated. But more trials are needed to prove the use of Sativex for other medical conditions.

Clinical trials are an expensive exercise. A recent Australian Sativex trial cost more than a million dollars. It was conducted over just nine days, with 51 people, and the drug was provided for free.

If Sativex needs to be paid for, costs will balloon. In New Zealand, where it is already available, medical cannabis users say an average prescription costs the equivalent of $1,000 Australian a month.

There are also questions about the effectiveness of drugs with one or two isolated molecules. Overseas users report preferring the raw plant with the combined effect of hundreds of molecules.

Advocates for legalisation say the call for more trials is just unnecessary. They point to a 2012 German study reviewing 100 clinically controlled trials on cannabis. The conclusion of that study is: 'There is now clear evidence that cannabinoids are useful for the treatment of various medical conditions.' You can find that study on our website. It not only reviewed trials of pharmaceutical products, but also a score of clinically controlled studies on the raw plant. The AMA even quotes this German review in its fact sheet on cannabis. Yet Dr Tony Bartone says that doesn't provide enough proof to legalise, or even trial the raw plant.

Tony Bartone: And some of those trials, the number of people enrolled in the trials were just too, too few. So it's at the stage now where we are really looking for larger, more multicentre trials, with data coming in from various sources, pooling and getting that information in a much more reliable, meaningful and statistically significant way.

Di Martin: The potential for clinical trials of any drug is endless. Where do you actually draw the line and say there is enough, as this study of 100 controlled clinical trials says there is now clear evidence?

Tony Bartone: What we wish to see is that we basically have the evidence that shows it's safe and effective to use in which conditions.

Di Martin: The problem is people are self-medicating, and they are seeing your members. So are you taking a position that, while safe, is irrelevant?

Tony Bartone: The safety of our patients is our primary concern. We need to be sure that we are doing no harm.

Di Martin: Back at Calvary Hospital in Canberra, Dr David Caldicott strongly disagrees, saying legalising medical cannabis is not a question of more science, but of braver politics.

David Caldicott: I think it's going to require bravery and leadership and a true moral stance rather than a default to the safest position.

Di Martin: You are a clinician supporting legalisation of medical cannabis. Not many of your colleagues are coming out are they?

David Caldicott: I think in Australia particularly a lot of my colleagues are afraid of the consequences of speaking out about this.

Di Martin: What are the consequences?

David Caldicott: The approbation of their colleagues. We are a conservative profession, there is no doubt about that.

Di Martin: Dr Caldicott says medical cannabis should be legalised immediately for a tightly defined group of people, beginning with the terminally ill and those with profound chronic conditions.

David Caldicott: This is an act of civil disobedience that is occurring already all over Australia. There are thousands of people doing this already. And so what we should probably look at is recruiting those who are already using it and seeing what effects it has on them. So an observational study in the first instance to see who is using it, why, to provide them with an amnesty so that they can come forward and not be afraid of prosecution. And I think that is a very good way to start.

What I don't think is useful is to put it in the hands of the pharmaceutical companies and to allow them to make enormous profits out of a product that actually probably can be consumed safely without detriment to the Australian taxpayer.

Di Martin: Background Briefing's co-ordinating producer is Linda McGinness, research by Anna Whitfeld, technical production by Simon Branthwaite, and Chris Bullock is executive producer. I'm Di Martin.