This now 7 year old World Health Organisation Overview on Cannabis Harms, whilst accurate and even predictive, is now looking a little 'light on' with data. 

The increasing bredth and depth of cannabis concern and carnage continues to grow and whilst pro-pot progagandist work tirelessly to bury this emerging data, the evidence of the short, medicum and long-term #harms of #cannabis continue to rise.

Excerpt 9.1.4 What do we know about the long-term effects of regular cannabis use?

We know the following:

  • Regular cannabis users can develop dependence on the drug. The risk may be around 1 in 10 among those who ever use cannabis, 1 in 6 among adolescent users, and 1 in 3 among daily users.
  • Withdrawal syndrome is well documented in cannabis dependence.
  • The health and social effects of nonmedical cannabis use
  • Growing evidence reveals that regular, heavy cannabis use during adolescence is associated with more severe and persistent negative outcomes than use during adulthood.
  • In a number of prospective studies there is a consistent dose−response relationship between cannabis use in adolescence and the risk of developing psychotic symptoms or schizophrenia.
  • The association between cannabis use and psychosis or schizophrenia has been recognized for over two decades in at least five ways:

1. Cannabis produces a full range of transient schizophrenia-like positive, negative and cognitive symptoms in some healthy individuals.

2. In those harbouring a psychotic disorder, cannabis may exacerbate symptoms, trigger relapse and have negative consequences on the course of the illness.

3. With heavy cannabis use, susceptible individuals in the general population develop a psychotic illness which is associated with age of onset of use, strength of THC in the cannabis, frequency of use and duration of use.

4. Cannabis use is associated with lowering the age of onset of schizophrenia it is likely that cannabis exposure is a “component cause” that interacts with other factors to precipitate schizophrenia or a psychotic disorder, but is neither necessary nor sufficient to do so alone. Symptoms of schizophrenia increase with cannabis use and strength. The magnitude of the symptoms is associated with the amount used and the frequency of use.

5. Daily use in adolescence and young adulthood is associated with a variety of negative health and psychological outcomes. These include:

  • early school-leaving
  • cognitive impairment
  • increased risk of using other illicit drugs
  • increased risk of depressive symptoms
  • increased rates of suicidal ideation and behaviour.




Dalgarno Institute Research Team