By Dr Janelle Trees, BSC (HONS), MBBS (HONS), FRACGP
Reaction against the use of cannabis for fun and pleasure was epitomised by the propaganda filmReefer Madness (1932) which portrayed smokers destroying their lives in sensational style under the influence of a joint (a ‘reefer’) or two and listening to jazz.
After recreational use of cannabis became popular in Australia in the 1960’s and 70’s, it took a few decades for researchers to document harmful side effects of recreational cannabis use in some people.
In the 80’s, GPs, Emergency doctors and psychiatrists saw patients who misused marijuana or had inadvertently smoked other substances laced in it which caused unexpected and unpleasant effects. Chronic cannabis misuse (called a cannabis use disorder) is associated with mood disorders, psychosis in vulnerable people, respiratory problems due to smoking and increased nicotine dependency.
Since about 2010 chemical mixes sold as synthetic marijuana with uncontrolled and ever-changing ingredients, sometimes seemed to cause or aggravate mental health problems in patients we saw. These artificially made substances were sold as legal and natural, but were seen to have unpleasant effects. A study of 1100 self-identified users of synthetic drugs, in a study supported by by the University of NSW, found that ten percent of users ‘felt like they would die’. Seventy-five percent of users said that they would not use it again.
Even regular, natural marijuana, overused in very high doses, can lead to a condition called hyperemesis cannabinoid. The patient cannot stop vomiting. The condition can puzzle doctors if the patient does not reveal their drug use. None of our regular medicines are effective to stop the heaving and vomiting, but a hot shower does. Other acute and more serious dangers of overuse of cannabis include an increased rate of fatal car accidents and suicidal ideations or tendencies. Too much of anything is never a good thing.
So research has made us wiser. We know that Reefer Madness was a hysterical overreaction. But is marijuana addictive?
In the popular understanding of addiction, almost anything that gives pleasure can be addictive. Some psychologists now posit that video games are potentially addictive because they stimulate dopamine, a neurotransmitter (brain chemical) associated with reward. Gambling, sex, shopping (called ‘addiction-like behaviours’) have the same effect.
Addictions to these ordinary things can devastate the lives of some people. We are not likely to see a health campaign on the potentially destructive financial and relationship effects of over-use of a David Jones credit card anytime soon, but they are real.
Doctors have been trained to use a strict definition of addiction. We apply it to chemicals that cause a physically (not just psychologically) stressful or dangerous withdrawal when the substance is abruptly stopped. By this definition, some of the medicines we prescribe and some illicit drugs are potentially very addictive.
And by this definition, marijuana is not very addictive. While people can and do become dependent on it in a detrimental way, it does not cause severe effects in withdrawal and the majority of users can give up fairly easily.
Opiates, (like Oxycodone) used for pain relief, mostly prescribed by doctors, are potentially deadly addictive substances. Benzodiazapines (like Diazepam) also have very high potential for addiction and tolerance, that is, you might need to take more of them over time to avoid painful withdrawal.
Alcohol and tobacco are by far the most deadly addictive substances our patients give themselves.
Patients are dependent on (as opposed to addicted to) many of the medicines doctors prescribe for them. Some medications can make a person very sick if they are stopped without warning. Paroxetine, an antidepressant, is an example. Patients can experience horrible nerve pain if they miss their dose.
Other medicines make our patients dependent because they need to the medicine to alleviate unpleasant or dangerous symptoms that return if they stop the medicine. A diabetic is not addicted to her insulin, but she is dependent on it and can get sick very quickly if denied access to the medicine.
About ten percent of recreational marijuana users are said to become psychologically dependent on the drug. They need help to find ways of coping and relaxing without it. This kind of dependency can be detrimental in young people who overuse the herb and avoid necessary maturation and social development, like going to work regularly and being able to have a conversation. Recreational marijuana is still an uncontrolled and illegal substance in Australia, which can also complicate users’ lives.
Medical marijuana is a different group of substances. Cannabis-based medicine is made from active constituents (cannabinoids) of marijuana, purified and regulated. It is only available to patients in Australia, who have a medical condition unrelieved by usual treatment. It needs to be a condition which evidence has shown may be responsive to the marijuana-based medicine.
The research is still inconclusive, overall, regarding which marijuana-based medicines help in which conditions and what the correct dose should be. Studies are mostly small and there are many types of marijuana, medicinal and otherwise, used in the studies. There is a consensus, though, that potential side effects of cannabis-based medicines are not serious.
Working with an Australian medical marijuana clinic, doctors are able to titrate the best effective dose, working closely with patients over a week or two, partly because of this.
If you get a little too much or try the wrong marijuana-based medicine for you, unwanted effects will be limited and you are likely to recover from them within a day or so.
It is sensible to avoid chronic and excessive use of medical marijuana in the developing brain, up to around age twenty-five.
For adults exploring the use of medical marijuana to treat symptoms of a disease or disorder under doctor’s supervision, evidence suggests that the risk of addiction is low.
If you have a history of addiction, or are in recovery, it is sensible to talk to your doctor about the risks and benefits of trying the medicinal marijuana. If you participate in a twelve-step program, talk to your sponsor or your specialist doctor about beginning medical cannabis, so that they can give you some extra attention, as they would when you were beginning any medication with potential psychoactive effects.
If you do have a history of addiction or drug misuse, your doctor might want you to be reviewed by a psychologist periodically or may make another suggestion in consultation with the medical cannabis team. There are some doctors using medical marijuana as a treatment for addiction, which will be the subject of another blog post.
We are all individual in our responses to medication, including those that have the possibility of making us feel good. Fear of dependency on medicinal marijuana should not be an obstacle to exploring its potential medical benefits.