Marijuana and Aggression

This information was prepared by the National Cannabis Prevention and Information Centre in Australia, and used with permission.  Some information may not be accurate for U.S. readers.

Does smoking marijuana cause aggression?

In general, after using marijuana a person experiences a sedating effect, which makes the drug less likely to cause violence in users than other substances such as alcohol and stimulants (e.g., amphetamines and cocaine).

However, sometimes when marijuana is used it can cause fear, anxiety, panic or paranoia, which can result in an aggressive outburst. For most people, however, once the effects of the drug wear off, their behaviour gradually improves.

Studies show that violence can occur more often among people who use marijuana regularly, rather than those who use it occasionally or not at all. It is unclear why this is the case, but it may be because people with violent tendencies can also have a range of other psychosocial problems and are therefore more likely to use marijuana. marijuana is also part of the illegal drug market, which may increase the chances of violence occurring in some social interactions.

Research also shows that marijuana users who commit violent acts usually have a history of violence before they start using the drug.

In addition, when people are withdrawing from marijuana they can be irritable, which can lead to abusive or aggressive behaviour.

Why do people become abusive or aggressive?

Using marijuana can produce strange behaviour and reactions in people when they are intoxicated. These reactions can be similar to psychosis and paranoia and because of this, marijuana users may experience the following:

• confusion – they misunderstand what is going on or what someone has said or done
• feeling threatened or frightened
• paranoia – they hear voices or think that people are out to get them

When people stop using marijuana they may experience a variety of withdrawal symptoms including:

• sleep disturbance
• irritability
• loss of appetite
• nervousness
• anxiety
• restlessness
• sweating

Experiencing any of these symptoms can make a person angry, which is an emotional response to feeling threatened or frustrated. Anger ranges from mild irritation to violent rage. Some people can express their anger in a controlled and constructive way while others lash out in an aggressive, uncontrolled way, either immediately or letting their feelings build up. This can lead to intimidating, violent or bullying behaviour, endangering them, other people and property.

How can you respond to threatening or violent behaviour?

The impact and the effects of violence on an individual can be profound and long-lasting, so doing all you can to prevent violence actually occurring is important.

The aim of calming someone down is not to prove them right or wrong, but to allow them to regain control of their behaviour without resorting to violence.

The best time to intervene is when a person is feeling anxious. Be supportive, empathic and neutral. Ask them what is wrong and try to calm them down. Move them to a quiet place and stay with them until the effects of marijuana wears off.

If a person's behaviour becomes aggressive, you could try the following tips to help calm them down:

• Before trying to intervene it is important to remember your own safety as well as the safety of the threatening person and all the people and things around them. If you think you can achieve a safe outcome for all, try to calm your friend down.
• Try to get other people who don’t need to be there to leave the area.
• Even if you’re scared and nervous, act calm. Use their name and talk in a soft, even tone – do not shout back at them. Have a relaxed posture and be non-confrontational.
• Don’t touch them.
• Ask them "What’s made you feel upset/angry?"
• Listen carefully and show empathy, acknowledging their concerns or frustrations without being patronizing.
• Let them know that you are here to help them. If there is something you can do for them, do it.
• Give them time to express themselves. Don’t hurry them.
• Keep them talking and ask open-ended questions.
• Be truthful.
• Help them set limits – "Come on mate, keep your voice down."
• Re-assess – is what you are doing working? If it’s not try something different or get help.
• If they calm down, try to distract them with other things that may take their mind off things.
• Stay with your friend until they and others are safe.
• Get them help if need be – Accident and Emergency, Police, other friends.
• If there is nothing you can do, retreat and get help.

After the effects of marijuana or marijuana withdrawal wear off, talk to your friend about what happened, how it affected you and those around you, and how this can be prevented in future.

How to help prevent aggressive and violent behaviour happening again

As a friend, you can do things that may reduce the likelihood of this happening to them again. These may include the following:

• Suggest they avoid marijuana use.
• If your friend has a mental illness like depression, anxiety or schizophrenia, encourage them not to take marijuana or any other drug, unless prescribed by a doctor.
• Encourage your friend to seek help from their GP or a counselor about their marijuana use and/or anger issues.
• Remind them of what happened last time they used marijuana.
• Suggest they avoid bingeing or polydrug use (using more than one drug at the same time), or anything that will intensify the effects of marijuana.
• Do other activities with them that don’t involve drug use.

Factsheet information taken with permission from the NCPIC web site.
Coming soon: updates to this page with U.S. data and information.