Some people think that marijuana is not truly “addictive” or that people can’t become “hooked” on the drug, but research shows that about 1 in 10 marijuana users will become addicted. For people who begin using before the age of 18, that number rises to 1 in 6.

Marijuana can cause heart disease with symptoms including: High heart rate and blood pressure, and an increase in the report of chest pains when exercising among people with existing chest pain.

There is no research showing that smoking marijuana early during pregnancy can result in miscarriage. Some studies have shown that marijuana use during pregnancy and future developmental and hyperactivity disorders in children.