Clearing the Smoke on Cannabis: Highlights

This report summarizes key findings presented in the Clearing the Smoke on Cannabis series. Topics covered in the Highlights report include: 1) regular use and mental health, 2) maternal cannabis use during pregnancy, 3) cannabis use and driving, 4) respiratory and cardiovascular effects of cannabis smoking, 5) medical use of cannabis and cannabinoids, 6) regular use and cognitive functioning, and 7) edible cannabis products, cannabis extracts and cannabis topicals.

Key findings include: 

• Regular cannabis use can increase the risk of developing psychosis and schizophrenia, especially among people with a family history of these illnesses.
• Using cannabis regularly prior to the age of 16 can lead to cognitive difficulties.
• Smoking cannabis regularly can lead to coughing, wheezing, sore throat, chest tightness at night, sounds in their chest, early morning phlegm and mucus, and bronchitis.
• There is limited evidence for a link between cannabis smoking and heart attack. Further studies are required to clarify whether heavy cannabis smoking is a risk factor for the onset of these complications.
• Using cannabis during pregnancy and breastfeeding can affect the development of the baby.
• Cannabis impairs the cognitive and motor abilities necessary to operate a motor vehicle and doubles the risk of being involved in a collision.
• Regular use of cannabis extracts or concentrates high in tetrahydrocannabinol (THC) is associated with tolerance, withdrawal and cannabis use disorder.