Get a Clue


Pin It


Marijuana is the most consumed illicit drug in the world, with over 192 million users. Due to the current legalization push of marijuana in the United States, there has been a lack of oversight regarding its public health policies, as marijuana advocates downplay the drug’s negative effects. This paper’s approach is from a public health perspective, focusing specifically on the cases of violence amongst some marijuana users. Here, we present 14 cases of violence with chronic marijuana users that highlight reoccurring consequences of: marijuana induced paranoia (exaggerated, unfounded distrust) and marijuana induced psychosis (radical personality change, loss of contact with reality). When individuals suffering from pre-existing medical conditions use marijuana in an attempt to alleviate their symptoms, ultimately this worsens their conditions over time. Although marijuana effects depend on the individual’s endocannabinoid receptors (which control behavioral functions, like aggression) and the potency level of tetrahydrocannabinol (THC) in the drug, scientifically documented links between certain marijuana users and violence do exist. Wider public awareness of the risks and side effects of marijuana, as well as a more prudent health policy, and government agency monitoring of the drug’s composition, creation, and distribution, are needed and recommended.

Introduction: In the United States, ten states have legalized the recreational use of marijuana and over 20 states have decriminalized the recreational use of it. Recent reports suggest, however, that the increase of the recreational use of marijuana is causing detrimental effects to individuals, as well as the society as a whole [1,2,3]. These effects include, but are not limited to, the increase of violence, the increase of thriving underground marijuana markets, and increase in car accident claims after the legalization of marijuana where the recreational use of marijuana was legalized [1,2,3]. This is caused by lack of oversight. Marijuana is being legally sold with high THC concentration levels without taking into account its addictive qualities and adverse effects. On the other hand, and contrary to popular belief, marijuana is still illegal in the Netherlands and it is decriminalized. However, the consumption and storage of marijuana are limited by law and the approach taken by the Netherlands is to decriminalize the drug in order to be able to help individuals struggling with marijuana use. This prudent oversight has resulted in a decreased in violence and people are able to get the care they need to deal with addiction and become less prone to violence [1,2,3].

Furthermore, the consumption of marijuana is associated with an increase in violent behavior over the course of an individual’s lifespan, a high risk of psychosis for frequent users, an increase of cardiovascular diseases, and deterioration in health for individuals who have pre-existing mental health issues such as Post Traumatic Stress Disorder, social anxiety, and depression [4,5,6].

According to research studies, marijuana use causes aggressive behavior, causes or exacerbates psychosis, and produces paranoia. These effects have been illustrated through case studies of highly publicized incidents and heightened political profiles.

These cases contain examples of repeated illustrations of aggression, psychosis and paranoia by marijuana users and intoxication. Ultimately, without the use and intoxication of marijuana, the poor judgment and misperceptions displayed by these individuals would not have been present, reducing the risk for actions that result in senseless deaths.

For full research

(The mounting anecdotal evidence of this growing and pervasive reality are recorded at Attacker Smoked Cannabis: suicide and psychopathic violence in the UK and Ireland – "Those whose minds are steeped in cannabis are capable of quite extraordinary criminality.")

Pin It

Moore and colleagues9 … found that individuals who had used cannabis had a significant, 1.4-fold increased risk of any psychotic outcomes, independent of potential confounding and transient intoxication effects. Findings also provided evidence for a dose-response effect, with even greater, 2.1-fold risk in individuals who used cannabis most frequently.

More recently, Marconi and colleagues10 performed a meta-analysis of 10 studies, including 66,810 individuals, that investigated the association between the degree of cannabis consumption and risk of psychosis. In all individual studies, higher levels of cannabis use were associated with increased risk of psychosis. They also found evidence for a dose-response relationship, with a 2-fold increase in risk for the average cannabis user, and a 4-fold increase in risk for the heaviest users, compared with non-users.

 For complete research

Pin It


Introduction: This paper compares consequences of cannabis use initiated after high school with those of cannabis initiation in adolescence, with estimates of the proportion of adverse consequences accounted for by adult-onset and adolescent-onset cannabis users.

Methods: A state-representative sample in Victoria, Australia (n = 1792) participated in a 10-wave longitudinal study and was followed from age 15 to 35 years. Exposure variable: Patterns of cannabis use across 20 years. Outcomes at age 35: Alcohol use, smoking, illicit drug use, relationship status, financial hardship, depression, anxiety and employment status.

Results: Substantially more participants (13.6%) initiated regular use after high school (young-adult onset) than in adolescence (7.7%, adolescent onset). By the mid-30s, both young-adult and adolescent-onset regular users were more likely than minimal/non-users (63.5%) to have used other illicit drugs (odds ratio [OR] > 20.4), be a high-risk alcohol drinker (OR > 3.7), smoked daily (OR > 7.2) and less likely to be in relationships (OR < 0.4). As the prevalence of the young-adult-onset group was nearly double of the adolescent-onset group, it accounted for a higher proportion of adverse consequences than the adolescent-onset group.

Discussion and conclusions: Cannabis users who began regular use in their teens had poorer later life outcomes than non-using peers. The larger group who began regular cannabis use after leaving high school accounted for most cannabis-related harms in adulthood. Given the legalisation of cannabis use in an increasing number of jurisdictions, we should increasingly expect harms from cannabis use to lie in those commencing use in young adulthood.

For complete research

Pin It

Is weed a gateway drug at any age? Frequent users are three times more likely to be heavy drinkers and 20 TIMES more likely to use other drugs - no matter when they start smoking marijuana

  • Researchers compared people who began regularly using marijuana as teenager and as adults to non-users 
  • People who began using pot as adolescents were 20.4 times more likely to be illicit drug users and 3.7 times more likely to be a high-risk alcohol drinkers
  • They were also 7.2 times more likely to smoke cigarettes daily and 0.4 times less likely to be in a relationship
  • Weed users who began as adults were 36.8 times more likely to use illicit drugs, 3.2 times more likely to be heavy drinkers 
  • These people were 7.3 times more likely to smoke cigarettes daily and 0.3 times less likely to be in a relationship

For complete article

Pin It


  • Peer deviance is associated with higher odds of cannabis use.
  • PRS is associated with higher odds of cannabis use among subjects who never engage with community activities.
  • Analyses in African American subjects were inconclusive due to limited portability of the PRS.
  • Church activities is associated with lower odds of cannabis use.


Background: Among adult college students in the US, cannabis use is common and associated with considerable negative consequences to health, cognition, and academic functioning, underscoring the importance of identifying risk and protective factors. Cannabis use is influenced by genetic factors, but genetic risk is not determinative. Accordingly, it is critical to identify environments that reduce risk among those who are at elevated genetic risk. This study examined the impact of polygenic scores for cannabis initiation, various forms of social activity participation, and peer deviance on recent cannabis use. Our aim was to test whether these environments moderate genetic risk for cannabis use.

Methods: Data came from a longitudinal sample of undergraduate college students of European American (EA; NEA = 750) and African American (AA; NAA = 405) ancestry. Generalized estimating equations with a logit link function were used to examine main effects and two-way interactions.

Results: Engagement with church activities was associated with lower probability of cannabis use. Peer deviance was associated with higher probability of cannabis use. Engagement with community activities moderated the influence of the polygenic risk score in the EA sample, such that PRS was associated with recent cannabis use among those who never engaged in community activities. This effect did not replicate in AAs, which may have been due to the portability of PRS based on EA discovery samples.

Conclusions: Results suggest that community activities may limit the influence of genetic risk, as associations between PRS and cannabis use were only observed among individuals who never engaged in community activities.

For full research




Frequently Asked Questions of Why We Are Opposed to Weed!

Get ya head straight!

Read More Now

cannabis info support

marvscn 350


video thumb

Marijuana Victims' Association
Windsor Morning

Busting the Myth
that Cannabis Doesn't Kill

  View Video 

Dr Kevin Sabet, C.E.O of Smart Approaches to Marijuana: Presents at the 20th NADCP Annual Conference

  View Video

The Marijuana-Opioid Connection

  View Video



sidebar add1


We provide a range of tools for educators to help deal with the issues of alcohol & other drugs
We provide a range of resources to help you deal with the issues of alcohol & other drugs
Find out what is happening in the world of alcohol & other drugs
Check out our selection of video clips on various topics

 Need Help?

  • Looking for help or at least thinking you really might need it?
  • Feeling a bit lost and alone and running out of options?
  • Maybe you're even thinking there is no way out?
  • well, you don't have to hit bottom to start looking for better options, pick up the phone and talk to somone who gives a damn.

Contact Help Line today...

Call 03 9583 2273 most times

PO Box 7005,
Dandenong, Vic, 3175
Telephone: 1300 975 002

Powered by Dalgarno Institute

logo header