Hallucinogens are a group of drugs that work on the brain to affect the senses and cause 'hallucinations' - seeing, hearing, smelling, tasting or touching things that do not exist. Hallucinogens are sometimes called 'psychedelic drugs', 'trips', 'magic mushrooms', 'LSD', 'acid'.

What are the forms of hallucinogens?

Some hallucinogens occur naturally in trees, vines, seeds, fungi (e.g. psilocybin or 'magic mushrooms') and leaves. Others are made in laboratories by mixing different chemical substances ('trips', LSD, 'acid'). Some drugs, such as cannabis and ecstasy, can cause hallucinogen-like effects when used in high doses or in certain ways. Using hallucinogens is often called 'tripping'.

LSD ('acid, 'trips') is the most often used form of hallucinogen. In its pure form, LSD is a white, odourless powder. This pure form is very strong, so LSD is usually mixed with other things to make the dose large enough to take. LSD comes in the form as liquids, tablets, capsules or squares of gelatine or blotting paper.

Psilocybin ('magic mushrooms') is the hallucinogenic chemical that occurs in some mushrooms. In its pure form, psilocybin is also a white powder, but it is usually sold as dried mushrooms or in substances made from mushrooms.

Psilocybin is from the same chemical family as LSD so their effects are similar.

Some people eat poisonous mushrooms thinking that they are the mushrooms that contain psilocybin. This can be very dangerous as some poisonous mushrooms can cause death or permanent liver damage.

What are the effects of hallucinogens?

• how much you take
• your height and weight
• your general health
• your mood
• your past experience with hallucinogens
• whether you use hallucinogens on their own or with other drugs
• whether you use alone or with others, at home or at a party, etc.

The effects of hallucinogens are not easy to predict. The effects are different for different people and at different times.

The main effects of hallucinogens are changes in the way you perceive things with your senses. They can include strange sensations, such as floating or your body becoming part of another object. Some people find such unusual sensations interesting and pleasant, while to others these same effects are unpleasant and disturbing.

Immediate effects

The effects of hallucinogens begin within half an hour of taking the drug, are strongest in three to five hours, and last for up to 12 hours.

They can include:

• seeing, hearing, touching or smelling things in a distorted way or that don't exist (you usually know that what you are sensing is not real);
• intense sensory experiences (e.g. colours become very bright, sounds become sharper);
• mixing of the senses (e.g. you 'hear' colours or 'see' sounds);
• changed sense of time (e.g. minutes can seem as slow as hours, or you can 're-live' something that happened a long time ago);
• space becomes distorted strange bodily sensations (e.g. as though you are floating or being pulled down by gravity, or that you are becoming part of another object);
• changed and intense thoughts emotional swings (e.g. change from intense happiness to deep sadness).

Effects on your body may include that:

• your muscles twitch
• you feel weak
• you feel numb
• your pupils get bigger
• you shake
• you feel sick or vomit
• your heart beats faster
• your blood pressure rises
• you breathe faster and deeper than normal
• your coordination is poor.

Bad trips

Sometimes the effects of hallucinogens are mostly negative. This is called a 'bad trip', and it is common among first time users. Effects of a bad trip can include:

• extreme anxiety or fear
• frightening hallucinations (e.g spiders crawling on the skin)
• panic, leading to taking risks (e.g. running across a busy street)
• feelings of 'losing control' or 'going mad'
• paranoia (feeling that other people want to harm you)
• suicide or violence (rare).

If someone you know is having a bad trip, they need to be reassured and comforted until the effects of the drug wear off. This can take many hours and may not disappear altogether for some days.

Long term effects

There are few known long term effects from hallucinogens. However, 'flashbacks' - times when you feel the effects of the drug again - can happen days, weeks or even years after taking the drug.

Flashbacks can include visual hallucinations and other effects. They can happen without warning, last for a minute or two and can be disturbing.

Flashbacks may be triggered by using other drugs or by stress, tiredness or physical exercise. Regular users are more likely to experience flashbacks than people who only use the drug from time to time.

Some other long term effects of hallucinogens may be damaged memory and concentration. Using hallucinogens may increase the risk of mental problems in some people.

Hallucinogens and pregnancy

LSD may be related to an increased risk of miscarriage, but little is known about the effects of LSD in pregnancy.

Tolerence and dependence

Anyone can develop a 'tolerance' to hallucinogens. Tolerance means that you must take more of the drug to feel the same effects you used to have with smaller amounts. With hallucinogens this happens very quickly. Being tolerant to one kind of hallucinogen (e.g. LSD) can also make you tolerant to other kinds ('magic mushrooms'). Tolerance goes away when you stop using the drug regularly.

'Dependence' means that a drug takes up a lot of your thoughts, emotions and activities.

'Withdrawal' means that if you stop or greatly reduce your intake of the drug, you will experience uncomfortable physical and mental signs.

There is little evidence that dependence or withdrawal syndromes exist for hallucinogens.

Hallucinogens and the law

Using, keeping, selling or giving hallucinogens to someone else is illegal.

Because hallucinogens change the way you see, hear, touch and experience other sensations, it is very dangerous to drive when you are under the influence of the drug. It is illegal to drive under the influence of drugs, including hallucinogens. Penalties include losing your licence, a fine and/or jail.

Source: NSW Department of Health