One of the most publicised beliefs about cannabis is that it causes schizophrenia and other mental illnesses.

However, at this very moment, people all over the world are getting relief from many debilitating illnesses; relief they wouldn’t ordinarily be getting from conventional medications. Many people wonder, why can’t Australians benefit from recent breakthroughs in herbal medicine?

Some believe the truth of the matter is that there is no clear evidence of a direct causal link between cannabis and schizophrenia but rather of an association. This is an important distinction. Evidence has shown that people with a personal or family history of a mental illness are at greater risk of triggering or worsening that mental illness and are thus strongly advised not to use cannabis, but cannabis itself hasn’t been proven to cause mental illness. In fact, anxiety, panic attacks, depression and other mental illnesses have all been treated successfully with cannabis and its components, all over the world.

Between 2003 and 2006 some 250 patients who suffered from a wide range of mental illnesses were treated in a Vienna practice with dronabinol, a component of cannabis.

In Austria the active ingredient of cannabis— tetra-hydro-cannabinol (THC) — has been legal for medicinal uses since 1998. Some 75, or 30%, of the tested patients suffered from depression, a sense of being overwhelmed or from burnout syndrome. For almost 80% of the patients, use of the medication led to swift improvement of the depressed mood or the sense of being overwhelmed. Only 20% of patients did not experience any significant mood brightening. To that group a combination therapy of dronabinol and a selective serotonin reabsorption inhibitor (SSRI), such as fluoxetine hydrochloride or a serotonin noradrenalin reabsorption inhibitor (SNRI), such as milnacipran, was administered.

The therapy generally resulted in rapid and satisfactory improvement of depression and the lack of drive. Side effects were generally low. Effective daily doses of dronabinol ranged mostly from 7.5 to 12.5 mg per day. Only few patients required a higher dosage, generally those also suffering from a sleeping disorder. The findings of this trial were published in an article called Treating Depression with Cannabinoids for the International Association for Cannabis as Medicine by the doctor who conducted the trial, Dr Kurt Blass.

National Director for the American Alliance for Medical Cannabis Jay Cavanaugh, PhD, wrote in his 2003 article Cannabis and Depression, published on the American Alliance for Medical Cannabis website:

“Numerous patients report significant improvement and stabilisation with their bipolar disorder when they utilise adjunctive therapy with medical cannabis. While some mental health professionals worry about the impact of cannabis on aggravating manic states, most bipolar patients trying cannabis find they 'cycle' less often and find significant improvement in overall mood. Bipolar disorders vary tremendously in the time spent in the depressive versus manic states. Those who experience extended depressive episodes are more likely to be helped with cannabis.”

Dr Cavanaugh then went on to write, “Patients who use cannabis to 'relax' may be treating the anxiousness sometimes associated with depression. Cannabis aids the insomnia sometimes present in depression and can improve appetite. Better pain control with cannabis can reduce chronic pain related depression. While cannabis cannot yet be considered a primary treatment of major depression it may improve mood when used under physicians’ supervision and in combination with therapy and/or SSRI’s.”

Unfortunately, the sorts of public trials performed by Dr Blass in Austria and others in the United States are nearly impossible in Australia due to cannabis’ illegality throughout the country. If a psychiatrist or a doctor wanted to follow their example they would have to commit a crime. That doesn’t mean the use of cannabis as medicine doesn’t happen in Australia. Whitsunday Health Service Deputy Director of Medical Services Dr Kenneth McCallum says that more often than not, especially in North Queensland, cannabis is both cheaper and more easily accessed than prescription drugs.

Dr McCallum says, “If a patient with cancer or some other problem were to come to us and say, ‘Look, this medication you’re giving me isn’t really working but I tried some pot and I feel a lot better.’ We would say, ‘Great, but we can’t prescribe that for you because it’s illegal.’”

Associate Director for Clinical Research Dr Stephen Sidney wrote the following in his 2003 article titled Comparing Cannabis with Tobacco – Again, published in the British Medical Journal:

"No acute lethal overdoses of cannabis are known, in contrast to several of its illegal (for example, cocaine) and legal (for example, alcohol, aspirin, acetaminophen) counterparts...

"Although the use of cannabis is not harmless, the current knowledge base does not support the assertion that it has any notable adverse public health impact in relation to mortality."

This opinion is supported by former US Surgeon-General Dr Joycelyn Elders, who wrote the following in her 2004 editorial published in the Providence, "Unlike many of the drugs we prescribe every day, marijuana has never been proven to cause a fatal overdose."

Freelance illustrator Lisa Manuzak was prescribed medicinal marijuana for her panic attacks when she lived in California. She says:

“It takes no great stretch of the imagination to assume that a government that doesn’t want to legalise marijuana, for medical use or otherwise, will only fund trials that will give negative results.”

The Australian Government still puts out fact sheets to the public that say: “… long term side effects of cannabis include development of mental illness...” as well as, “Marijuana is a gateway drug that can lead to the use of more serious drugs such as cocaine and heroin.”

An Australian paper, Reforming the Old and Refining the New: A Critical Overview of Australian Approaches to Cannabis written by Maurice Rickard says:

“Cannabis use that is not heavy and sustained (but which is occasional and recreational) generally does not involve the same significant risk of health related harm; except for particular contexts such as operating vehicles or machinery.”

The gateway theory has also been called into question by new research done by the University of New Hampshire in the USA.

Conducted by UNH Associate Professors of Sociology Karen Van Gundy and Cesar Rebellon, the research appears in the September 2010 issue of the Journal of Health and Social Behaviour. The researchers found that whether teenagers who smoked pot will use other illicit drugs as young adults has more to do with life factors such as employment status and stress. In fact, the strongest predictor of whether someone will use other illicit drugs is their race/ethnicity, not whether they ever used marijuana. The journal reads:

"While marijuana use may serve as a gateway to other illicit drug use in adolescence, our results indicate that the effect may be short-lived, subsiding by age 21. Interestingly, age emerges as a protective status above and beyond the other life statuses and conditions considered here. We find that respondents 'age out' of marijuana's gateway effect regardless of early teen stress exposure or education, work, or family statuses."

It would appear that Australia is missing out on the potential medical breakthroughs that could be possible with a more lenient legal standpoint on the drug. Considering the biggest fear associated with cannabis is its potential for developing mental illness in its users, perhaps a rethink is in order regarding its criminal status given the success overseas psychiatrists are having treating their patients with the drug and its components.

Regardless of the political or social agendas those in power have that kept cannabis on the list of criminally offensive drugs, the possible medical benefits should first be explored. If a prescription of cannabis can give a bi-polar man fewer mood swings or help a cancer patient on chemotherapy to eat, then maybe it’s worth exploring. What have countries like Austria, the USA and others that have at least legalised cannabis for medical use, discovered about the drug that still eludes Australians?

Cannabis is a genus of flowering plants that includes three putative species, Cannabis sativa, Cannabis indica, and Cannabis ruderalis, with cannabis sativa being the predominant species used for recreational use. Dronabinol and nabilone are cannabinoids, which are medicines created synthetically from chemical components of the cannabis plant. The term “medical marijuana” means the use cannabis or cannabinoids to treat a mental or physical illness.