Cannabis in Australia

Mild euphoria, relaxation and reduced inhibitions. Some might say that smoking cannabis or marijuana is a beneficial recreation. Known for its ability to intensify, negatively as well as positively, everyday, ordinary experiences, Cannabis can, however, start to alter perceptions of reality and to distort time – things that start to get a little more serious. Further short-term effects can include panic reactions, confusion and feelings of paranoia. Nausea can develop, along with headaches and increased heart rate – for up to 3 hours after smoking. Dizziness, impaired balance and poor coordination can soon follow.

Longer-term, the effects can be even more serious, leading to physical dependence and disease. Upper respiratory tract cancers, chronic bronchitis and permanent damage to airways can develop from smoking Cannabis, as can cardiovascular system damage. The risks are not only physical. Smoking Cannabis can lead to deterioration in mental health conditions including depression, anxiety and schizophrenia. Among younger smokers, Cannabis can lead to poor adolescent psychosocial development.


Availability and Consumption

Cannabis is widely and easily obtainable throughout Australia. The primary source of Cannabis is through friends (66%) followed by dealers (20%). Some 35% of Australians, approximately 6.9 million people have smoked Cannabis in their lifetime, and 10.4% (2.1 million Australians) have used Cannabis within the past 12 months.


What is Cannabis?

Cannabis comes in 3 main forms:

Herbal, also known as marijuana. This is the weakest form, comprising the dried leaves and flowers of the cannabis plant.
Resin, known as hashish, which is derived from the dried resin of the plant, and Oil, extracted from the resin. This is the strongest form.

Cannabis is usually smoked in a hand-rolled cigarette (“joint”) or water pipe, but it can also be consumed when added to food. The oil variant can be heated and the vapours inhaled. The main psychoactive compound of the cannabis plant is delta-9-tetrahydrocannabinol (THC). Cannabis also contains a further 70 unique chemicals, known as cannabinoids. Cannabis is a central nervous system depressant, it can alter sensory perceptions and may produce hallucinogenic effects when used in large quantities.


Cannabis and Mental Health

Ongoing and regular use of cannabis is associated with a number of negative long-term effects. Regular users of cannabis can become dependent and commonly report symptoms of withdrawal, including sleep anxiety, sleep difficulties, appetite disturbance and depression.

A survey by the Australian Institute of Health and Welfare AIHW in 2017 shows significant increases in the reported cases of depression, anxiety, schizophrenia, bipolar disorder, eating disorders and other forms of psychosis.

A study by the NDSHS conducted in 2016 found that between 2013 and 2016 the number of cases of mental illness, including higNDSHSh to very high levels of psychological distress reported by regular Cannabis users rose from 20% to 27%.



The use of cannabis is also highly correlated with the use, and abuse, of alcohol, tobacco and other drugs, which makes it difficult to measure the impact and risks of cannabis alone. The same 2016 NDSHS study shows that alcohol is the most prevalent substance used concurrently along with Cannabis. Some 65% of Cannabis users exceed the monthly risk guidelines for alcohol consumption, and a total of 41% exceed the lifetime risk guidelines.

While alcohol is the leading co-occurring substance, it’s by no means the only one. Some 17% of “recent’ Cannabis users also used Ecstasy, 16% Cocaine and 14% used prescription medications recreationally.

It would seem that Cannabis as a lifestyle choice isn’t necessarily as benign as might be imagined. The AIHW 2017-2018 Alcohol and Other Drug Treatment Services National Minimum Data Set (AODTS NMDS) showed that Cannabis was a principal drug of concern in 22% of closed treatment episodes and was the third most frequently reported principal drug overall. In almost half (46%) of cases where Cannabis was the principal drug of concern, patients reported additional concurrent drugs of concern including alcohol (in 33% of cases), nicotine (25%) and amphetamines (21%).

The 2019 Illicit Drug Reporting System (IDRS) shows that Cannabis is the most frequently used illicit drug across the whole sample of people who inject drugs, with 74% reporting use in the previous six months. People who inject drugs may seek to alleviate their withdrawal symptoms by smoking Cannabis. Others may use Cannabis, in combination with other drugs to enhance their effects.


Who is at risk?

Almost seven out of ten patients in cases where Cannabis is the drug of concern are male (actually 67%). The average age of cannabis users has increased from 29 years old in 2001 to 34 years old in 2016. Approximately one in six (18%) are from the indigenous population. Where cannabis is the principal drug of concern, indigenous Australians are eight times more likely to receive treatment than non-indigenous Australians.

The 2016 NDSHS study shows that twice as many indigenous Australians smoke Cannabis per population compared to non-indigenous. The study also shows that people identifying as homosexual or bisexual are 3.2 times more likely to report recent use of cannabis compared with the general population.


Criminal Justice System

The most common source of referral for treatment episodes where Cannabis is the principal drug of concern is the criminal justice system, where some 32% of cases are referred into AOD treatment for drug or drug-related offences. This compares to 28% of cases where referral is by the patient themselves or their family.

In 2017 – 2018 72,381 arrests, the highest number on record in Australia, were arrests relating to cannabis, increasing 30% over the last decade from 55,638 in 2008 – 2009. Consumer arrests accounted for 92% of national cannabis arrests in Australia. According to the Drug Use Monitoring in Australia (DUMA) programme, approximately 46% of all detainees arrested tested positive for cannabis use. A figure on a par with the proportion of detainees tested positive for amphetamines (45%).
The 2018 Prisoner Health Survey reports that 40% of prison entrants reported using Cannabis within the previous 12 months, second only to amphetamines (43%).


Medicinal Cannabis

In 2016 the Australian Parliament passed legislation to enable the cultivation of cannabis for medicinal and related research purposes. The changes came into effect on 30 October 2016. Medicinal Cannabis products are available for specific patient groups under strict medical supervision.

There are currently reviews either completed or still underway to assess the use of cannabis in treating Epilepsy in both children and adults; MS (multiple sclerosis); side effects of chemotherapy and HIV/AIDs therapy including nausea and vomiting and for chronic pain management and palliative care. Cannabis cultivated for other purposes remains illegal.



Where Cannabis is the principal drug of concern in cases in Australia, counselling was the most common form of treatment, with some 39% of cases being referred for counselling.

If you are concerned about cannabis use by yourself or a loved one, contact one of our trained counsellors at Miracles Asia for a free, confidential discussion.

Please Contact Us to arrange a confidential discussion about how we can help.


Miracles Asia Rehab PhuketSources:
AIHW 2017
ACIC 2019a, NSW MoH 2017
ACIC 2018, NSW MoH 2017
ACIS 2019a
Hall & Degenhardt 2009, Nielsen & Gisev in press
ACIC 2019a, ACC 2010
DoH 2017
Peacock et al 2019b