Marijuana and Aggression
Does Smoking Marijuana Cause Aggression?
Marijuana usually has a sedating effect on most users, making it much 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, once the effects of the drug wear off, their behavior gradually improves.
Some studies have found support for an association between marijuana use and various types of violence, including relationship or interpersonal violence (Moore TM & Stuart GL, 2005). However, no definitive correlation between marijuana use and violence in adults has been establish; the correlation appears to be stronger in adolescents (Copeland J, Rooke S, Swift W, 2013). Violence in anyone, including marijuana users, often has a multicausal explanation, with numerous factors impacting behavior, such as increased life stress, aggressive personality traits, multidrug use, or a history of violent behavior (Macdonald S, et al., 2008). Marijuana is also part of the global illegal drug market, which may increase the chances of violence occurring in some social interactions.
Additionally, when people are withdrawing from marijuana they can become irritable, which can lead to abusive or aggressive behavior among people with a history of aggression (Smith PH et al., 2013). Studies have not found an association between withdrawal symptoms and aggression among those without a previous history of aggression.
Why Do People Become Abusive or Aggressive?
Using marijuana can produce strange behavior 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 confusion or a sense of feeling threatened or frightened.
When people stop using marijuana they may experience a variety of withdrawal symptoms including:
- sleep disturbance
- irritability or restlessness
- loss of appetite
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 behavior, endangering them, other people and property.
How Can You Respond to Threatening or Violent Behavior?
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 behavior 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 behavior 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.
- 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.
- Keep them talking and ask open-ended questions.
- Be truthful.
- Reassess – 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 – call other friends of 911.
- 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. See also the Looking After a Friend factsheet.
How to Help Prevent Aggressive and Violent Behavior From 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, especially if they have a mental illness.
- Encourage your friend to seek help from their doctor 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.
- Copeland J, Rooke S, Swift W. Changes in cannabis use among young people: impact on mental health. Current Opinion in Psychiatry 2013;26(4):325-329. View abstract
- Macdonald S, Erickson P, Wells S, Hathaway A, Pakula B. Predicting violence among cocaine, cannabis, and alcohol treatment clients. Addictive Behaviors 2008;33(1):201-5. View abstract
- Moore TM, Stuart GL. A review of the literature on marijuana and interpersonal violence. Aggression and Violent Behavior 2005;10:171-192. View abstract
- Smith PH, Homish GG, Leonard KE, Collins RL. Marijuana withdrawal and aggression among a representative sample of U.S. marijuana users. Drug & Alcohol Dependence 2013 (in press). doi: View abstract
This information adapted with permission from the National Cannabis Prevention and Information Centre in Australia.