In the past, people used to think that cannabis wasn’t as dangerous or addictive as other so-called ‘harder’ drugs such as heroin or cocaine. There is increasing evidence however, that shows that cannabis is linked to mental health issues, health problems such as lung diseases and that it can cause dependence and withdrawal. Different drugs affect different people in different ways. For some people, cannabis is a particularly dangerous drug.

Using cannabis can have unpredictable effects. Everyone reacts differently to cannabis and so it can’t be said that only those who use it for a long time or in high doses will be badly affected or experience any problems with it. It is important to remember that cannabis is a drug which has been linked to mental health problems including depression, and that young people in particular have been shown to be particularly vulnerable to its effects.

‘Greening out’ is a term that refers to the situation where someone feels very sick after smoking cannabis. If this happens, users can go pale/green and feel sweaty, dizzy and nauseous.

‘Greening out’ is similar to an overdose, with some people even reporting passing out after using cannabis. Combining cannabis with alcohol appears to make the likelihood of someone ‘greening out’ greater.

If someone has a bad reaction after using cannabis, take them to a quiet place with fresh air, sit them in a comfortable position and give them a glass of water or something sweet (such as juice or a piece of fruit). If they start vomiting it is important not to leave them alone, even for the shortest time. Stay with them and lie them down on their side, not on their back, so they do not choke on their vomit. If you feel they are getting worse or you are really worried about them, get medical assistance.

The main active ingredient in cannabis is called delta-9 tetrahydro-cannabinol, commonly known as THC. This is the part of the plant that gives the ‘high’.

The flowering tops, or ‘buds’ of the female cannabis plant have the highest concentrations of THC, followed by the leaves. The seeds and stalks have much lower levels of THC. Hashish, made from the resin (a secreted gum) of the cannabis plant and hash oil, thick oil obtained from hashish, contains more THC than the dried flowers and leaves.

‘Hydro’ refers to cannabis that has been grown hydroponically, or indoors, using artificial light sources such as lamps. Some people think ‘hydro’ is stronger than naturally grown cannabis, but studies have not found any convincing evidence to support this. It is possible that hydroponic growers choose cannabis varieties which are more potent anyway, or grow the plants to reach their full genetic potential which might make people think it is stronger.

‘Bush buds’ is a term used by regular cannabis users to describe cannabis that has been grown naturally, i.e., not hydroponically.

It would appear that the strength of cannabis has increased to some extent over the last 25 years. It might seem stronger as these days more people smoke the stronger parts of the plant such as the flowering heads or ‘buds’ rather than just the leaves as they used to. Also, using a bong is more popular now which may increase the amount of cannabis and thus THC smokers are exposed to.

People who grow cannabis to sell on the black market try to maximize their profits by growing as much as they can in the shortest time possible. A wide range of chemicals and fertilizers are used, many of which we know very little about, particularly in terms of what effect they will have on the smoker’s health. There have also been some cases where growers and sellers have added substances such as lead particles and glass beads to enhance the weight and appearance of the cannabis.

Using, possessing, growing or selling cannabis is illegal across Australia, however the penalties for cannabis offences are different in each state and territory. Penalties include fines, being charged with a criminal offence or even being sent to jail.

Young people who are caught with cannabis face legal consequences. Diversion schemes are often used however, to divert young people from the court system and work on reducing the risk that they will reoffend. These are different in each Australian state and territory but can include education programs, counseling, official cautioning and warning systems.

Drug detection (or ‘sniffer’) dogs can be trained to detect many things, from drugs to explosives and even to counterfeit DVDs. Cannabis, heroin, amphetamines and cocaine are among the types of drugs sniffer dogs have been trained to detect.

Dogs have a highly developed sense of smell which therefore makes it possible for them to detect cannabis on your clothes if, for example, you had recently been with friends who had been smoking around you.

Obviously staying away from people while they are smoking cannabis will prevent sniffer dogs from detecting traces of the drug on your clothing. It is important to remember that sniffer dogs’ highly trained sense of smell means that even the tiniest amount of cannabis in your clothes will be detected.

Using, possessing, growing or selling cannabis is illegal across Australia, however the penalties for cannabis offences are different in each state and territory. Penalties include fines, being charged with a criminal offence or even being sent to jail.

Decriminalised means that the offence will not result in a criminal charge and can be dealt with by a civil penalty, such as a fine. It is important to remember that this does not mean the offence is legal or that there will be no consequences. States and territories that have decriminalised minor cannabis offences include South Australia, Western Australia, the Australian Capital Territory and the Northern Territory.

Each state and territory has its own laws so it is important to know the cannabis laws in your jurisdiction. There may also be different laws for young people and adults, resulting in different consequences.

The laws for cannabis offences are not exactly the same for young people and other Australians such as adults. Diversion schemes are often used to divert young people from the court system and work on reducing the risk that they will reoffend. These are different in each Australian state and territory but can include education programs, counseling, official cautioning and warning systems.

The cannabis cautioning system allows police to have an alternative to charging adult offenders for minor cannabis offences so they do not receive a criminal record. It is different in each state and territory but can include a system of cautions if people are found with small amounts of cannabis for personal use or equipment like bongs. Usually, the system requires people to attend education or health sessions about cannabis. The cautions are not unlimited however, and if a person keeps reoffending, more serious consequences may follow. New South Wales, Queensland, Victoria and Tasmania all operate cannabis cautioning systems.

Records of criminal history as a juvenile are not destroyed when you turn 18 years of age. If you have received a caution as a juvenile that will be kept on the police computer and is not destroyed.

Many jobs, including nurses, doctors, teachers or people working in the armed services, require employees to have a criminal records check. Having a drug conviction could result in a person not being eligible for some employment positions. In addition, people with a criminal record may have difficulty in gaining entry and visa approval to certain countries, including the USA and many parts of Asia. There is also a certain social stigma attached to people with a criminal record which can be hard to deal with, especially for young people.

When someone becomes ‘dependent’ on a drug it means that they need more and more of a drug for it to have the same effect. It also means if they stop taking it, they may experience withdrawal symptoms such as irritability, trouble sleeping and feeling depressed. Wanting to stop but not being able to, or spending too much time obtaining, using or recovering from cannabis use are other signs of dependence.

In the past, people didn’t see cannabis as a drug of dependence in the same way as heroin or alcohol, but cannabis dependence is now well recognised in the scientific community.

Seeing a counsellor can help cannabis-dependent people reduce how much they use, as well as improve their wellbeing. Speaking to a health professional, such as your family GP, is another thing you can do to get help and advice.

Counselling is one of the most popular treatments for people who have problems with cannabis. It can teach effective strategies to cope with cravings, avoiding high-risk situations where they might relapse and use cannabis, and help them to work out why they want to cut down or quit.

Different drugs affect different people in different ways. Cannabis has been shown to be a drug of dependence and so whether or not you become dependent is more to do with your habits of use, rather than there being something wrong with you individually.

A psychotic episode is usually a short-term, temporary period of time when a person has difficulty in telling the difference between what is real and what is not. They might hear voices that are not really there (hallucinations), or believe things that are not true (delusions). Sometimes their thinking or speech is muddled which makes it hard for people to understand them.

There is no evidence that says cannabis causes mental illness, however it has been linked to illnesses such as schizophrenia, depression and anxiety. Evidence has shown that cannabis use may trigger schizophrenia in those who are already at risk of developing the disorder and that people who use cannabis have higher rates of depression. In terms of anxiety and panic disorders, although cannabis can cause short-term symptoms of anxiety, it is not seen as an important risk factor for chronic, long-term anxiety disorders.

People who start using cannabis at a young age and use it frequently are more likely to experience mental health problems. Because young people’s brains are still developing, it is important that they do not put their brains at risk by using drugs such as cannabis.

In itself, cannabis is not a direct cause of violent behavior. If cannabis has triggered a psychotic episode and the person feels threatened or is suffering from delusions or hallucinations they may act violently. Additionally, if they are experiencing withdrawal symptoms they may be irritable and more prone to aggression.

Usually, the psychotic episodes people experience after using cannabis are short-term and go away once they stop using. In some cases, however, cannabis use can trigger a mental illness such as schizophrenia, particularly in a person who has a predisposition to it or a family history. This is why it is very important that young people avoid experimenting with or regularly using cannabis, in case they are vulnerable to developing a mental health problem.

The most important thing to remember is to check for danger and ensure that your safety is not at risk. A person who is affected by drugs in this way can be extremely dangerous – never put yourself at risk. Call 000 so that they can be treated quickly and safely.

If you believe you are not in danger and you can reason with them, try to calm them down, reassure them that these feelings will pass in time, take them to a safe, quiet place and tell them that you are here to help them. If there is nothing you can do then it is important to get more help as soon as possible.

Cannabis, like other drugs such as alcohol, negatively affects your driving ability. As a result, driving under the effect of cannabis is illegal in all states and territories of Australia and may result in a fine, license suspension or imprisonment.

Roadside saliva tests undertaken by police can detect the presence of THC (the active component in cannabis), methylamphetamine (speed) and MDMA (ecstasy). Blood tests, which are far more accurate, are usually used to confirm the results of the saliva tests.

In early 2008, roadside drug testing was being carried out in nearly all jurisdictions in Australia with the exception of the Australian Capital Territory (ACT) and Northern Territory (NT). In the NT, roadside drug testing can only be carried out on other motorists if they are involved in a car accident or identified as driving dangerously. The ACT Government is currently reviewing relevant roadside drug testing legislation.

Roadside drug testing can detect THC, the active component of cannabis, methylamphetamine, also known as speed, ice, crystal meth, or base and MDMA, also known as ecstasy.

The saliva tests are designed to only react to active ingredients in the drug. This will vary with the drug and the quality and quantity of the drug which has been used. Unlike a blood test, where a person who has smoked cannabis can be detected weeks later, the roadside drug test can only detect THC for a short time after.

Driving under the influence of cannabis increases the risk of a motor vehicle accident two to three times. Also, if cannabis is used with alcohol at the same time, even at low doses, it could have a worse effect on driving than either cannabis or alcohol alone.

Cannabis does not improve your driving skills but is much more likely to worsen them. Cannabis can negatively affect reaction time, attention, decision making, time and distance perception, short-term memory, hand-eye coordination and concentration.

Passive smoking is when the smoke from a substance someone is smoking is breathed in by people around them. It can include the smoke breathed out by the smoker (‘mainstream smoke’) as well as the smoke coming from the burning substance (‘sidestream smoke’).

Both tobacco and cannabis smoke are harmful. They both contain carcinogenic chemicals such as tar and have been linked to cancer and respiratory diseases. Usually, a greater volume of cannabis smoke is breathed in, inhaled more deeply and held in the lungs longer than tobacco smoke is, making the risks of health problems occurring higher. Adding to this, the water in bongs makes the smoke cooler and therefore easier to smoke.

Any type of passive smoking, be it cannabis or tobacco, will expose a person to the negative health effects of that smoke. Respiratory diseases such as bronchitis and lung cancer have been linked to passive smoking. Although the effects of cannabis will be lower from passive smoking than active smoking, they will still exist.

Cannabis can be detected in a saliva test from passive smoking up to 30 minutes after exposure. The evidence for urine tests and hair tests is not as clear. It is important however, to not only remove your risk of being tested positive to cannabis if those around you are smoking it, but also to protect your health by staying away from cannabis smoke.

Apart from the effects of passive cannabis smoking, being around people who smoke cannabis regularly may lead to someone experimenting with the drug as they may come to see it as something normal and acceptable. They might not have as much interest or time to be involved in other, healthier activities and this could lead to other things suffering, such as sport or their school work.

Cannabis is usually smoked. It can also be cooked or baked in foods and eaten, or drunk in tea.

The most common way to use cannabis is by smoking it. This can be done in a variety of ways, such as:

• a pipe
• a joint (a ‘roll your own’ cigarette)
• a waterpipe or ‘bong’
• a vaporiser

Bongs are the most common method in Australia, especially among young people. They can be made from a variety of materials such as glass, plastic and aluminium. The cannabis is packed in a ‘cone’ and burned, and water is used to cool the smoke before it is inhaled.

There is no safe way to use cannabis. All methods of use have some degree of risk. One of the greatest risks is linked to the smoking of the drug, i.e., the user inhales burned matter, increasing the risk of a range of health problems. When a cannabis user eats the drug they remove this risk. All of the other health risks linked to cannabis still exist however, such as possible mental health problems and dependence.

There is no safe way to use cannabis. All methods of use have some degree of risk.

The most harmful way of smoking cannabis is through a bong. Although inhaling smoke through water makes it cooler, this makes it easier for the smoker to inhale a greater volume of smoke more deeply into the lungs. This increases the surface area for tar and other carcinogens to affect the respiratory system.

Everyone who uses cannabis will have a different experience. Sometimes these experiences may be extremely frightening. If this happens to someone you know, try to do the following:

• try to calm the person down
• reassure them that these feelings will pass in time
• take them to a safe and quiet place and stay with them
• let them know that you are here to help them. If there is something you can do for them, do it
• if they calm down, try to distract them with other things that may take their mind off things