There has been a lot in the news recently about decriminalising the use cannabis, so a major review on the effects of the drug in the scientific journal Addiction should help inform debate.

Cannabis does not produce fatal overdoses, the review says, but 1 in 10 of regular users will develop a dependence syndrome (this rises to 1 in 6 among those who start using it in adolescence).

Regular use that starts in the teens and continues into young adulthood appears to produce ‘intellectual impairment’. It approximately doubles the risk of being diagnosed with schizophrenia or reporting psychotic symptoms in adulthood.
Regular cannabis smokers also have a higher risk of developing chronic bronchitis. No surprise there!