Cannabis and dependence

Typically, people who use cannabis do not progress to using the drug regularly, or for long periods of time. Most will experiment every now and then with cannabis during adolescence and early adulthood and stop using once they are in their mid to late 20s. However, some people will use cannabis for longer and more often, and become dependent on the drug. Historically, cannabis was not seen as a drug of dependence like heroin or alcohol, but cannabis dependence is now well recognised in the scientific community.

What is cannabis dependence?

Dependence on cannabis means that the person needs to use cannabis just to feel normal .

In order to be diagnosed as cannabis dependent, a person needs to experience at least three
of the following in the one year:

  • tolerance to the effects of cannabis, meaning that more cannabis is needed to get the same effect;
  • withdrawal symptoms from cannabis, such as irritability, trouble sleeping and depressive symptoms;
  • using more cannabis than was intended;
  • persistent desire to stop using cannabis or to cut down and being unsuccessful at this;
  • spending a lot of time obtaining, using or recovering from the use of cannabis;
  • giving up important activities in favour of using cannabis; and/or
  • using cannabis even when it is known that it causes problems

What are the consequences of being dependent on cannabis?

People who are dependent on cannabis are at a higher risk of suffering from the negative consequences of using the drug, such as short-term memory impairment, mental health problems and respiratory diseases (if cannabis is smoked). Regular use and dependence can also lead to problems with finances, conflict in relationships with family and friends, and employment problems.

How many people become dependent on cannabis?

It has been estimated that there are at least 200,000 people dependent on cannabis in Australia. About one in ten people who have tried cannabis at least once in their lifetime will become dependent on it. The more often a person uses cannabis, the more likely they are to become dependent on it. If someone uses cannabis everyday, they have a 50/50 chance of becoming dependent on it. Young people develop cannabis dependence more quickly than adults.

Who are most at risk of being dependent on cannabis?

The earlier a person starts using cannabis, and the more they use, the more likely they are to become dependent. Studies have shown that males are more likely than females to become dependent on cannabis.

What are the symptoms of cannabis dependence?

One of the most common symptoms of cannabis dependence is the experience of discomfort when ceasing use. This is known as withdrawal. Studies with cannabis users who have recently quit, report that withdrawal symptoms start on the first day, usually peak in the first two to three days, and with the exception of sleep disturbances, are usually very mild by the end of the first week of abstinence. Withdrawal symptoms are usually over after two weeks.

The most common symptoms include:

  • anxiety/nervousness
  • restlessness/physical tension
  • reduced appetite
  • mood swings/irritability/restlessness
  • cravings to smoke cannabis
  • sleep difficulties including insomnia and strange dreams

Even though these symptoms are not life threatening, they can be distressing enough for the person trying to stop using cannabis, to start again.

Is there any treatment for cannabis dependence?

There are a number of treatment options available for cannabis-dependent people to cut down or quit. Studies have shown that even a single session with a counsellor can assist the cannabis-dependent person to bring about significant improvements in their level of use and wellbeing.

The intensity of treatment depends on individual circumstances; some people respond to general education and information about managing cravings and high risk situations for relapse, others may even need inpatient management for cannabis withdrawal and rehabilitation. As yet, there are no effective pharmacological treatments to help reduce cannabis withdrawal symptoms or to block the effects of cannabis, although studies are underway.

Factsheet published June 1, 2008. Updated October 1, 2011.