• 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, and deterioration in health for individuals who have preexisting mental health issues, such as PTSD, social anxiety, and depression.
  • Examples of highly publicized incidents include marijuana users who exhibit aggression, causing exacerbation of psychosis and paranoia.  Without the use of and intoxication by marijuana, the poor judgment and misperceptions displayed by these individuals would, perhaps, not have been present, reducing the risk for actions that result in senseless deaths.
  • Most started using cannabis as youth and were daily or frequent long-term users of high-potency cannabis.  Some were diagnosed with marijuana-induced psychosis and paranoid disorder, and some “heard demon voices.”  They would consume large amounts of marijuana to try to silence those voices, causing greater paranoia and hallucinations, mood swings, anger, and violence.  Many were depressed and suicidal.  Several tested positive for a high concentration of marijuana/THC in their system at the time of arrest after the crime. 
  • Today’s marijuana is far more potent with THC concentrations up to 99%.  More potent marijuana results in a greater risk for paranoid thinking and psychosis.  In turn, paranoid behavior increases the risk for even more aggressive and violent behavior.
  • Studies found that one-third of prison inmate subjects who committed homicide had used marijuana 24 hours before the homicide.  Three-quarters of those inmates were experiencing at least one mental or physical effect from marijuana intoxication when the homicide occurred.  A Review of Cases of Marijuana and Violence-NCBI) AAML
  • Paranoia and hallucinations from marijuana sometimes lead perpetrators to commit violence.  A Review of Cases of Marijuana and Violence NCBI, NIH  
  • Individuals medicate the distress and pain that comes from difficulties with lack of protective coping mechanisms when they become distressed.   Individuals who use cannabis are likely to report dysfunctional coping as a primary reason for substance use. 
  • Marijuana use reduces one’s empathy, which may explain why many shooters do not care about the victims and why the Boston bomber placed his explosive right by a child.  Indeed, studies show that marijuana blunts a person’s emotions.  (Medical News Today, Cannabis Use Affects Processing of Emotions, March 1, 2016.)