Cannabis is derived from the cannabis plant (Cannabis sativa). It grows wild in many of the tropical and temperate areas of the world. It can be grown in almost any climate, and is increasingly cultivated by means of indoor hydroponic technology.
The main active ingredient in cannabis is called delta-9-tetrahydrocannabinol, commonly known as THC. This is the part of the plant that gives the ‘high’. There is a wide range of THC potency between cannabis products.
Cannabis is used in three main forms: marijuana, hashish and hash oil. Marijuana is made from dried flowers and leaves of the cannabis plant. It is the least potent of all the cannabis products and is usually smoked. Hashish is made from the resin (a secreted gum) of the cannabis plant.
It is dried and pressed into small blocks and smoked. It can also be added to food and eaten. Hash oil, the most potent cannabis product, is a thick oil obtained from hashish. It is also smoked.
Cannabis is usually smoked in hand-rolled cigarettes (known as ‘joints’) or in special waterpipes (‘bongs’). These pipes or bongs can be bought or made from things such as orange juice containers, soft drink cans or even toilet rolls.
Cannabis is the most widely used illicit drug in Australia. According to the 2010 National Drug Strategy Household Survey, 35.4% of the Australian population reported using cannabis at some time in their lives, with 10.3% having used it in the last 12 months. More than 700,000 Australians used cannabis in the previous week.
The proportion of secondary school students reporting using cannabis has decreased in recent years. However, the 2008 Secondary School Survey still found that cannabis was the most commonly used illicit substance by this group, with 14% of all secondary school students aged between 12 and 17 years reporting using the drug at some time in their life.
Cannabis use increased with age from 3% of 12-year-olds who had ever used cannabis to 26% of 17-year-olds.
Cannabis is also known as marijuana, grass, pot, dope, Mary Jane, hooch, weed, hash, joints, brew, reefers, cones, smoke, mull, buddha, ganga, hydro, yarndi, heads and green.
Most people who use cannabis do so to experience a sense of mild euphoria and relaxation, often referred to as a "high". Cannabis causes changes in the user's mood and also affects how they think and perceive the environment, e.g. everyday activities such as watching the television and listening to music can become altered and more intense.
The short-term effects of using cannabis may include:
There is limited research on the long-term effects of cannabis. On the available evidence, the major probable adverse effects are:
There is also much concern about the link between cannabis use and mental health problems and the risk of dependence. For further information on these issues please refer to the cannabis factsheets on mental health and dependance.